A few hours before I was due to meet Marco Pierre White for lunch I was warned by a friend who once worked with him that he would try to seduce me. 'He does it to everyone,' she said, with a resigned air. Not that I needed to be told. Marco is famous for hosing down his interviewers with serious liquor. The last time OFM dispatched a journalist it was two bottles of Chateau d'Yquem, the most expensive white wine on the face of the planet; by the time he had finished filling the glasses our writer was practically petitioning Rome to fast-track an application for beatification.

I, however, am made of sterner stuff . It certainly takes more than a bottle of 1970 d'Yquem to get me on my knees. (A case, perhaps? Maybe two?) In any case we are hardly starting from a neutral position, Marco and I. It's true that despite my six years as a restaurant critic and his two decades as chef and restaurateur, we had never met, not properly. The first time I set eyes on him was only a few months ago, when I was reviewing his new upmarket pizzeria, Frankie's in Knightsbridge, which he believes will be the source of a coming fortune. I thanked him briefly for a good meal on the way out (because it had been), but only as an anonymous punter.

In print, though, I have never been afraid of letting the great MPW have it with both barrels. In the late Eighties when he made a splash at Harvey's in South London, winning his first two Michelin stars within a year of each other, being crowned the new wunderkind of British gastronomy and throwing what he considered the appropriate hissy fits, I was yet to pull my chair up to the table. A few years later he moved to the Hyde Park Hotel, where he became the first British-born chef and the youngest anywhere in the world to win three Michelin stars. Now I wanted to know what all the fuss was about.

It was - and remains in real terms - the most expensive meal I have ever bought with my own money, at £267 for two. It was also the most joyless. I remember almost nothing of what I ate, save a pig's trotter dish that he had cooked in homage to the chef, Pierre Koffman. The rest was a dismal procession of prissiness plated more for design than taste. What I do recall is the funereal atmosphere of the up-itself dining room, the gloomy demeanour of the staff and the sommelier who suggested a £75 bottle of wine when we had asked for something at £50.

Later I had an equally dreary meal at the Criterion on Piccadilly Circus, one of the first restaurants Marco took over as proprietor rather than chef. The food was bad - clumsy chicken Kiev - the service worse. Then there were the raging arguments I used to have with his PR guru, the late Alan Crompton-Batt, a friend of Marco's and the man credited with igniting the media frenzy that developed around him. Crompton-Batt accused me of ignoring Marco's chefs in an article on rising stars of the kitchen, while favouring those of Gordon Ramsay. There could be no greater sin in Marco's eyes because the two have long been at silent war, even though Ramsay was once his protege. And it's true that I had, but only because no one knows who Marco's chefs are. He collects restaurants: the Mirabelle, Quo Vadis, the Belvedere, L'Escargot, Wheelers, Drones. Ramsay collects personnel - Angela Hartnett, Marcus Wareing, Mark Sargeant, Jason Atherton - and opens restaurants around them. I had even managed to get into a row with one of Marco's oldest friends from school days, a chef called Simon Gueller now at the Box Tree in Ilkley, who had initiated legal action against me over one of my reviews. Marco is famed for his loyalty to his oldest friends. What will this huge bear of a man with those vast meat-plate hands do to me, when we meet for real at Frankie's?

He will, as it turns out, offer me a drink. He likes a drink does Marco, like a fish enjoys water. I decline. I know where that one can lead. 'You knew my old mate Alan didn't you?' he says. Yes, I say, cheerfully, and I didn't drink with him at lunchtime either. Marco laughs a big hearty laugh and orders himself a glass of white wine. He didn't start drinking until he stopped being a chef when he was 38, but he seems to have picked up the basics. 'He was a good boy, was Alan,' he says, lighting another in a long line of cigarettes. Good, so we won't be scrapping over that then. Marco gives me a big friendly grin so that his eyebrows rise towards his newly buzzcut hair. He was famous for his tangle of flowing locks but, as of a couple of days before, that has all gone. I am looking at the new model Marco. And that, it seems, will be the theme of our day: goodbye cheffy, food-obsessed Marco. Meet the new business model MPW, well into his forties, but streamlined and ready for action.

He launches into a long anecdote about the Box Tree where he had one of his first kitchen jobs in the late Seventies. With us are a very blonde PR girl called Rebecca and a very dark chap called Jeremy from the company Global Brands, who are both here to make sure we talk about a new range of saucepans that Marco is helping launch with the kitchen utensils company Beka. They hang on his every word, and laugh at his jokes and generally do the things you should do around a big man like Marco who wants an audience, which is to say, be one. I mention the Simon Gueller business, briefly, and Marco bats it away. We won't be arguing over that either, then. 'It's clear he likes you,' Rebecca says quietly at one point, like he's some huge St Bernard, whose moods can be discerned only by the eager pant of his tongue.

When I arrive at Frankie's it is empty. The huge disco balls on the ceiling turn silently to themselves, scattering the walls with fragile jewels of light. The leather tablecloths are undisturbed. For years now Marco has been attempting to find a restaurant concept that he could roll out from this site, just down the road from Harrods. First it was the Chophouse Parisienne, a classic French bistro, but that failed. Then it was a place called Chez Max, also a French bistro, but that didn't do either. The Frankie's concept, which is a joint venture with the jockey Frankie Dettori, is working because the proposition - good quality Italian food, great service, nice price point - is so simple. And their crispy shards of battered courgette are to die for. They are about to open another one in west London and shortly after that the Criterion will be converted into a Frankie's too.

I ask him how much of the business he owns. 'I own nothing of it,' he says coolly. I'm sorry? 'If you own things in life you have a responsibility to them. I don't want responsibility. I'm not a director. I'm not a shareholder. I have no income from it.' This is, frankly, bizarre. Since he hung up his apron in December 1999 , announcing that gaining three stars had been fun but that 'maintaining them was boring', he has been linked with a dizzying number of business ventures, from Planet Hollywood, through a sandwich company, to those myriad restaurants. Now he is telling me he doesn't own anything. Which is curious, because I'd spent the morning on the Companies House website, where he is listed as a director of half a dozen companies. Of course you can be a director without owning a share, but still it seems odd. We would have to investigate this later.

For now we were off to lunch at Drones, a Belgravia dining club named after the fictional club in PG Wodehouse's Jeeves books, which Marco opened with the nightclub promoter Piers Adam, two years ago. His driver, Mr Ishi, will transport us all in Marco's Range Rover which is waiting outside, its expensive seats protected by thick covers. 'Sorry about those,' Marco says. 'I use this car when I go deer stalking. Do you hunt? Would you like to hunt? We could go hunting.' I say I haven't and that I couldn't imagine myself doing so any time soon. I'm a nice Jewish boy from North West London. Undergrowth is not my natural habitat. 'Any country pursuits at all then? Fishing? Anything like that?' I say no and he looks disappointed. Marco is famous for styling himself as a country squire. He even owns a pub down in Hampshire, the Yew Tree near Highclere Castle. 'Are you a pub man?' I say yes, because I can't bear him to think I'm a complete lady boy, though I'm not a pub man. 'Lager or beer?' I know what I'm meant to say so I tell him I love bitter, though of course I don't.

Still, he has at least revealed that he owns a pub, which he describes as his 'pension'. What about Drones? How much of that does he own? 'I don't anything of it. I sold my share to Ben Goldsmith because it didn't fi t in to my future plans. I told you I don't want the responsibility of owning things.' Jeremy, the brand man, who is desperate to make sure we talk about the Beka saucepans, now pipes up. 'You do own the White Heat collection.' Marco sniffs. 'No I don't. I own the brand. Owning things takes up too much time.' It's going to be a long afternoon.

At Drones, a pleasing wood-panelled space with nice mobiles hanging from the ceiling and some terrible paintings on the walls, we trail across the dining room, all part of Marco's entourage now. I notice he has his initials embroidered on the breast of his white shirt. Waiters in this club that he doesn't own swarm about him, like so many paparazzi attending to a minor royal. Over the menus - good club food like potted shrimps and fishcakes and sausages - we talk restaurants. 'What I love about my career was that I saw the old world, like the Box Tree and Michel Bourdin at the Connaught. Then came the golden age of gastronomy, Albert Roux, Nico Ladenis, Pierre Koffman. The people who replaced that, they all pretend to cook when they don't cook.' It would seem that he's referring to Gordon Ramsay here though, whenever he does refer to people by name, he insists it's off the record. Marco is renowned for falling out with people - the actor Michael Caine, the artist Damien Hirst, his mentor Albert Roux, Ramsay - but it doesn't sound like he wants to pick a fight today. 'The reason I gave up cooking was because it became a job, not a way of life. I could have stayed a prisoner of that world. I could have lived a lie and not been in the kitchen. Or I could give up cooking and reinvent myself. The problem was I became unemployed. I don't have a job any more.' I thought you were a businessman? 'If anything, I'm just becoming a businessman. I'm beginning to understand it now.'

Later in the conversation, however, he denies he's a businessman at all. So what about all those companies he's a director of? Companies with names like Sellican, MPW Criterion and Baker's Dozen? He responds with a completely unintelligible explanation of what those companies do, designed to reveal nothing.

I try another tack. Looking at the accounts of companies with which Marco has been involved what becomes most obvious are the losses they have made. MPW Criterion for example, had losses in 2001 of over £4 million, double that of the year before. Its liabilities, when people to whom it owed money were thrown in, amounted to £9.7m. By 2003, the last year for which fi gures are publicly available, the liabilities had dropped but still topped £3m. 'Those losses can be used against profits,' Marco says. And then, 'If you had £10m in creditors and debts you wouldn't be in business, would you? But we are.' What does he make of all the press reports about his business dealings, the ones that say his restaurants are in trouble, the others that say he's worth £50m? 'Doesn't bother me. Why should it bother me?'

His enthusiasm for this conversation has noticeably cooled. Before he was expansive, gregarious. Now he looks at me suspiciously as if I'm trying to catch him out. Rebecca the PR girl shifts uncomfortably in the seat next to me. I ask him who owns the Mirabelle. 'I don't know,' he says expressionless. What restaurants do you have interest in? 'No idea.' I ask him about Baker's Dozen, a company he acquired only a few weeks ago. What is it? 'It's a company.' What does it do? 'It has interests.' What sort of interests? 'Interests can take many forms.' And in this case? 'Food.' This is getting tedious. I am, after all, a journalist. I point out that I'm here to find out stuff, not talk in riddles. He grabs my notebook and sketches out a standard MPW business deal in diagrams. It is, he says, all off the record and at the end rips the page out the notebook and stuff s it in his pocket, like a naughty schoolboy with a fi lthy doodle. It doesn't make any difference because it's completely opaque.

The fact is that trying to get to the bottom of Marco's business empire is like trying to follow one of his recipes: a job only for the professional. As long ago as 2001 it was announced that he was stepping down from the company that owned the Mirabelle, Quo Vadis and all the others, but that he would remain as a shareholder and consultant. His long time business partner, the restaurateur Jimmy Lahoud, is certainly still involved and the accounts of the various companies that Lahoud and Marco have been a part of regularly refer to personal loans made by the men to those companies, and consultancy fees going back the other way, but those only give a snapshot of what has been.

It is certainly the case that a very complex network of companies is involved, so complex indeed that many experts have given up trying to ascertain his value. Marco was estimated to be worth £50m in the Sunday Times rich list for 1999. In 2000 that was down to £35m, and he disappeared altogether the following year.

'I've been unable to see evidence of the profits to justify his inclusion in the list,' said Philip Beresford, who compiles the list, at the time, and Beresford kept him out again this year. In the past Marco has happily allowed the media to describe him as the proprietor of the restaurants in his group. What's changed is that he no longer does so, preferring instead to refer elliptically to his 'interests in restaurants'.

The only thing I could ascertain from his furious scribbling in my notebook is that a share of the companies with which he is involved goes to an offshore trust. He does not own that trust but he does control how that block of shares votes on important issues. As he says, absolutely correctly, he does not own the restaurants. But he has a bloody big say in what happens to them. So far so muddy. Even my hunger for the truth is waning. Lunch arrives, thank God: those potted shrimps to start for me, and just the two starters for him, some Parma ham and a dish of veal tonnato. I suggest we talk about his new saucepan range as much to change the subject as anything else. 'No, let's not talk about pans,' Marco says. Rebecca and Jeremy are bereft. Marco wants to talk about restaurants again, his restaurants. 'I like building restaurants for the people,' he says, grandly. 'I realised I couldn't educate people but I could feed them.' So is that's what he's doing at Frankie's? He nods. 'We're in the business of selling fun at a price point. The food and drink is secondary.'

It is, I point out, exactly the opposite of what he would have said when he was in his Harvey's days striving for Michelin stars with dishes like tagliatelle of oysters with caviar and roast Bresse pigeon with ravioli of wild mushrooms and truffle fumet. 'True. I would have said it was all about the food. But I've changed. The world has changed. I have no desire to go to Michelin- starred restaurants any more. I've been there and done that. I like the word eating house. I want to create places for people.' Did he lose his interest in high end gastronomy the day he hung up his apron? 'I think it died way before that, when I won my three stars. Until that it was a way of life. After that it was a job and I don't like jobs. Now I have a way of life again.' He describes himself as a humble man from humble beginnings. Yes, but he must like the trappings of his new life? 'Like?' Like Mr Ishi, his driver waiting outside, like the pub, the big house in Holland Park. He shrugs. 'Not everyone wants a pub. I need a car and I need a house for my kids.' It's as simple as that. He's just a family man, with his wife Mati and their three kids and his country pursuits and all the interests in businesses he doesn't own.

What does he think, then, of the current crop of chefs? Time for another cigarette. 'The problem with many chefs today is they want too much too young.' There speaks the youngest three-star chef ever, the man who is credited by many people in the industry with inspiring a huge number of young kids to enter the profession. 'No, not guilty,' Marco says. 'I never tried to be a celebrity chef. I was always in the kitchen.' Indeed he was. And it was there in the kitchen that he was photographed in grainy black and white by Bob Carlos Clark for White Heat, possibly the most influential recipe book of the last 20 years. There was Marco in grimy apron plating up, or opening scallops, looking every inch the piratical hero, with his long black hair and sunken eyes and high cheek bones, surrendered long ago to his new-found affluence.

I have interviewed at least a dozen top-ranking chefs over the years who have cited that book as a huge influence. And not just the food. They wanted the life. The image. Marco's image. Marco refuses to accept that had anything to do with it. 'It was Michelin launching in Britain in 1976. That gave chefs something to aim for.' Rebecca is trying to get us to move onwards to North London where a photographer is waiting for us but Marco is having none of it. He wants another cigarette. He wants another glass of wine. He insists on having pudding. And then an espresso to follow. And make sure it's a big one. It doesn't matter that only half an hour ago he described himself as a stickler for punctuality and that, now, we will be late. 'I'm enjoying this,' he says. He tells me I'm good to talk to, that he enjoys a good back-and-forth chat and irritatingly I find myself flattered. He is, as I had been warned, strikingly charismatic. He does have a habit of talking in banal Hallmark homilies - 'working hard is an attitude of mind' or even, redundantly 'everything I did is in the past' - and his 'new best mate' shtick is so blatant it's almost funny. He wants to take me fishing. He wants me to go to his pub with him. He wants to eat fi sh with me at Wheeler's, another of the restaurants he doesn't own.

Eventually we heave him out the door and, as we drive, Jeremy and Rebecca force him to talk about the pans. For years people have been inviting him to put his name to products, he says, but he hadn't bothered. Then Beka said he could design the pans. So they've come up with five ranges in a variety of finishes from non-stick to luscious brushed copper, which are much easier to keep clean. Though I am usually deeply suspicious of celebrity-endorsed cookware, these are rather lovely: substantial, shapely, as they should be at a starting price of £50 rising to £250. 'A good pan has got to be an extension of you,' he says. 'It's about the feel, the distribution of weight.' But he soon drops away into a morose silence as Jeremy and Rebecca chatter on about how Marco's been out on the road endlessly promoting the pans and about how they really are his designs. The ranges are called White Heat and the promotional material is illustrated with one of the pictures of Marco in his glamorous undernourished youth. Did he not worry that his name wouldn't mean that much to people any more? 'No I didn't think about that,' he says . It doesn't matter, says Jeremy. They're launching in 17 countries, most of which really have never heard of him. Apparently it is just about the pans, then.

At the studio, Marco falls quickly into position, fag at lip, Panama hat in place, while our photographer Harry sets to work. I ask him if he enjoys the process. 'No,' Marco says. 'I've been doing this for 20 years. It's a long fucking stint.' He cheers up when Harry suggests Marco and I be photographed together. Immediately Marco says, 'We should hold hands', and he takes mine firmly in his. So I stand there, shoulder to shoulder with this huge man, thinking we must look like two big gay bears and cursing myself. The whole point of this was not to let him seduce me. I was not meant to be bowled over. Instead I'm standing here looking like I'm now his bitch. And it didn't cost him a single drop of Château d'Yquem, let alone two bottles. I have been firmly Marcoed. It is, I decide, time to go home.

· Marco Pierre White's White Heat cookware is available from branches of Debenhams, Selfridges and John Lewis. (www.beka-cookware.com).