This year I have been travelling around the British Isles making a series for Channel 4 called Don Roaming in pursuit of local essence. Perhaps a better way of putting this is that I have been trying to establish what differentiates one place from another. This was prompted partly by the revulsion that most of us feel at the bland uniformity of so many high streets with their chain stores selling the same items in the same positions on identical shelves. Wind up in a hundred small towns all over Britain and there is an immediate sense of sickly déjà vu. Go into most pubs, fast food outlets or cafés and the 'home-made' pie is probably identical to the one you foolishly ate two weeks before and 100 miles away, because both were made in the same factory in Croydon. The idea of local identity seems to be rapidly becoming historical. But I was also intrigued by a remark made to me 20 years ago by an old gardener. When I asked him where he came from he said 'My people belong to Aberdeen'. I have since learnt that it is a pretty standard way for Scottish people to say where they come from but it exactly describes what I was looking for. Not many of us feel that we belong specifically to a nation although most of us have somewhere that feels like where we belong. And I wanted to see behind the hideous conformity of globalised, homogenised life, the things that measure out locality: accent, weather, soil, crops, industry, custom and food.

In all the programmes that we were making, I actively sought out local food wherever I could find it. On the one hand I suspected that local ingredients, recipes or eating habits would tell me a lot about a place, and on the other I wanted to see for myself what we really are eating. Most of our generalisations are based on what we read and what we and our tiny circle of friends do. Mine certainly are. As someone passionately committed to organic gardening and organic food I clearly had a bias towards seeing what the supposed huge increase in organic consumption actually looked like at ground level. Was organic consumption spread evenly right across the country or was it, as I suspected, a metropolitan fad? Certainly BSE and foot and mouth had made us more suspicious of our food. For decades we have slavishly believed what politicians, scientists and food companies have told us. Now we know that many are lying, greedy bastards, concerned only with the health of their shares and not in truth or a healthy nation. Nothing new there then, but it is refreshing to have it out in the open. Was this translating into fresher, healthier, more varied food around the country?

But it was not a food programme and given the compromises and constraints of television this often meant that we overlooked it in our finished programmes. However, a film crew lurches from meal to meal with passionate, focused intensity. It needs to eat often and it wants to eat a lot. We were all issued £25 per day which was to cover lunch, dinner and any other drinks or snacks that we felt necessary. The figure stayed the same whether we were in central London, Dudley or a village in Yorkshire. So every day had a serious mission of finding the best places to eat and drink within our budget.

The results ranged from the farcical to the occasional delight with a vast middle ground of repetitive, depressingly bad food. We ate 'out' for every meal for weeks on end. This produces an odd state of anticipation. On the one hand hunger has to be appeased. On the other hand you are very aware that you are paying more for the occasion and the setting than for the food itself, so even on a financial level you want to enjoy these things apart from the human desire to celebrate the end of another day.

When I am not filming I rarely eat away from home other than the odd lunch on jaunts to London. This is not because I dislike restaurants in principle but simply because I nearly always eat better either at home or in other people's houses. To go 'out' for a meal far too often means having worse food than normal. Every night while I was away I would call my wife to say goodnight. We would talk about our respective dinners and throughout the spring and summer I reckon I ate 79 restaurant dinners. Only three were memorable and only five times did we mutually agree that I had gone to bed better fed than her. Half the time the food I ate was just poor - the kind of thing that you ate solely for nourishment and in order not to offend the company that you were with. The other half of the time the essential difference between Sarah's meals at the kitchen table at home with the children and mine was the simple preparation of the freshest, best seasonal ingredients.

The role and status of organic food when eating cheaply outside London is problematic. There is an unshakeable correlation between cheap food and mass production. It is shocking how little importance vegetables are given - let alone fresh, seasonal organic ones. If I ever asked what variety a certain vegetable was I was instantly branded a troublemaker. Which I surely was. In fact if I was feeling bolshy - and I was, I was - the best way to stir up trouble was to ask any kind of detailed question about the menu: what kind of beef cattle did the steak come from? Where was the cod landed? Was the cauliflower grown locally? Dream on.

For some of the time we had a vegetarian in our crew and she found it extraordinarily difficult to eat well. Every menu had a token dish 'suitable for vegetarians' but at best dull and often disgusting. I don't think that this is anti-vegetarian, although they are still a tiny minority outside the big cities - but an anti-vegetable thing. The concept of a dish of beautifully prepared beans or spinach is wholly alien. From the south coast of Dorset to the Moray Firth vegetables appeared either as a side-order with half a dozen unseasonable, overcooked tasteless offerings in a dish, or as a garnish.

In the chain hotels and restaurants you come to expect this with a kind of weary resignation - inspecting the laminated menu for the least-worst option, trying to decode messages in the descriptions spawned from an unholy marriage of catering college and a marketing department peopled by those who couldn't pass the estate agency exams. 'A rich melange of surf'n'sand seasoned with nature's fruits on a succulent bed of chef's pasta.' Always run screaming from anything that has the word 'chef' attached to its description on the menu - because it will confirm the fact that everything that is not qualified in this way is being unwrapped from its foil as you read and the microwave switched to the appropriate setting. Also 'chef' sits in the kitchen like a threat. The other day I was lunching in an expensive and self-consciously trendy new restaurant in London, when the waitress asked me if I enjoyed my soup. When I told her that, in fact, I had not because it was tasteless, she replied with a lifted brow, 'I will be sure to let chef know what you thought'. And walked off leaving me to guess what cocktail of bodily fluids would be added to my main course.

The worst crime of middle-range restaurants - and that is nearly all restaurants - is pretension. In 10 months I only came across about three places that made a virtue of simplicity. Are we all so ignorant of how good food can be that the majority of people that use these places simply do not realise how bad they are, or is it that we know but do not care?

In smaller set-ups I always clung to the naïve belief that there might be that perfect combination: simple, unpretentious food with personal character and service. Sometimes this was exceptional. I had the best steak I have ever eaten in my life at the Bank House hotel in Fettercairn, Aberdeenshire, served rare, using local Aberdeen Angus beef. Perfect. But that was a special place.

But special places can often be spoiled by a small-scale aping of the dreadful chains. Everywhere we went butter and jams were served in those horrible individual portions. Service was nearly always slow and unresponsive to our actual demands or needs. We accept this as part of the British character because, I suspect, secretly we admire it. Being good at service means that we are servile and toadying and demeans our noble island spirit. Bollocks. Crap service is part of our class system where the underdogs rebel against their inferior impotence. If giver and receiver of service respect each other as equals then both parties will want the best available. It is about being a good host and that is rare in Britain today.

So much for behind the scenes. My gastronomic tour of Britain journey started on a clear windy day in the middle of march in South Wales at Crofty on the Gower peninsular. There are only 55 licences to cockle on the Gower and another 150 on the waiting list which is currently around 30 years. Some people put their children down for Eton at birth, others on the Gower cockling list. Gathering takes place three hours after high tide and I went out with Brian at midday to watch the day's cockle harvest. It took an hour to drive there in the Land Rover, fording streams and bogs down to the estuary overlooking Llanelli. It is a vast muddy flatness rippled like the roof of a dog's mouth. The cockles live just below the surface of the muddy sand which the cocklers scratch aside with short-handled garden rakes. They can gather up to 30 tons a day in summer, which is around five million cockles, each one raked and sieved by hand. They work in small groups around a tractor and trailer, splay legged, bodies bent almost double, raking with a short-armed frantic scratching through the inch deep water as though peeling away the surface of the estuary. The cockles are sieved, leaving the smaller ones to grow and reproduce and the larger ones, around three or four years old, are bagged up and taken back to the factory where they placed on a conveyor belt, cooked for four minutes, shelled, cleaned, and weighed into punnets. The unit that I visited catches an average of two million cockles a day and sells them all. The demand is there.

Now a cockle is a delicious thing. They are particularly good raw, like an oyster, eaten under a great estuary sky, opened by using one cockle to twist open another, a wonderful fresh salty and sweet taste. Brian would only eat them like this and popped one into his mouth every few minutes as he worked. The cockles travel all over the world from the Gower but I also tasted their laver bread which is made entirely for a local market, going no further than Cardiff in the east or Carmarthen in the west. Laver bread is a gloopy sauce of stewed seaweed (in this case the purple Porphyra laciniata) gathered off the Pembroke coast. It is rich and intense, almost mushroomy in flavour and delicious. The local people eat it for breakfast, hot with bacon. It is interesting how folklore builds up around local food. I was assured that laver bread was a nineteenth-century Welsh invention, intended to provide a cheap source of nutrition for the women and children working down the mines. Dorothy Hartley, in her Food in England points out that it was a medieval food and very popular in eighteenth-century Bath. She also catches the initial experience of eating it perfectly: 'Laver has a queer iodine taste - few people really like it the first time, but once you have the taste, you want more.'

As different as possible from the salty freshness of cockles were the faggots I ate in the Black Country. Faggots developed as a way of using up all the bits of pig that would otherwise be discarded. This section of the pig, the 'fry' consists mainly of the lungs, thorax, liver, heart. The only bit of pig you cannot use, I was told slightly more often than I could convincingly smile at, is its squeal. Everything goes into the mincer with some onion and sage. The result is an offal meatball which is wrapped in the pig's caul. It is then roasted and served with gravy and mushy peas or 'payse'. It is cheap but slow food. The modern hamburger or kebab relies on a dumper truck to scoop up the scrapings from an abattoir floor for their ingredients and superficially a faggot is a more low-tech version of this, but there are vital differences. For a start each batch of faggots comes from one animal. You can know exactly what breed it was, what it was fed on and - this is important to me - how it was kept during its life. Each hamburger can come from hundreds of different animals, all of which arrive to the consumer utterly anonymously.

I had to judge a faggot contest among 15 master butchers. It was impossible of course but interesting on two accounts. The first was the range of tastes. They varied enormously from a kind of hot paté to a meaty dumpling. Each one had character. None, incidentally were organic. The reason given was that faggots were a cheap food. An organic version would be appreciably more expensive and they didn't think that the demand would justify it. Again and again I kept coming back to this factor of organic food being a well-heeled, middle-class option. The second factor was the intense and serious interest in faggot-making. Faggots have a powerful symbolism in the Black Country and eating them is a statement of identity and belonging.

In North Yorkshire I had a fascinating time with a butcher who made his own pies that I wrote about in these pages in June, using entirely local ingredients without any chemical input, but not certified organic. He produced the best pork pie I have eaten made from a pig that was running free on his farm three days earlier. It seems to me that this kind of local produce rises above the semantic political correctness of organic or non-organic. We should celebrate that kind of local food at every opportunity and local hotels should promote it - which, in my experience, they shamefully do not do.

I also spent some days in Whitby. Its fishing industry is on its knees, but you can still, thank good eat some of the best fish and chips in the world there. I remember a deeply depressing experience of going to a fish and chip shop in Wales - Fishguard I think - within sight of the moored fishing boats and being told that it would take 20 minutes to be served because the fish was still frozen.

The Magpie restaurant is just across the road from the fish market Whitby and they sell that day's catch, as fresh as any fish could be. The restaurant is unpretentious and it is cheap. Now, here is an ideological quandary for the right-on eater: do you eat cod or not? I adore fresh cod and think that it makes by far the best fish and chips, but stocks are dangerously low. Every time you order it you create a demand. In the north of England and in Scotland they rate haddock higher and that is what I ate in Yorkshire, but cod is almost always better.

We went on up into Scotland to the east coast, which I had never visited before. In Aberdeen I ate rowies for breakfast. These are a flat bap with a very high fat content that taste like a very salty, slightly doughy croissant. They began life as a way of using up excess fish oil and fishermen took them to sea as a convenient way of consuming calories. There is a sense of waterproofing yourself as you eat one, especially when they are served, as they often are, with a huge amount of butter. It is an acquired taste, but Aberdonians love them and eat them by the tens of thousand. I visited a family bakery that made 5,000 a day using the same oven that they had been baking with for the past 50 years. Like them or not - and I came away unconverted - rowies subvert the appalling global food culture with a deeply satisfying disregard for the attempt to please all the people all the time. They belong to Aberdeen.

My favourite bit of foodieism came when I visited Alford oat mill, run by Donald Macdonald (tel: 01561 377356 www.oatmealofalford.com). Donald is passionate about oats. His oatmill was built in about 1870 and his family has run the mill since 1894, using pretty much the original techniques. It is unique, certainly in Scotland. The attention to detail is meticulous and obsessive. The oats are spread to dry almost to toast on the top floor which is made of pierced steel plates. This immediately makes them different - and better - than the standard oatmeal. Drier oats - his have less than four per cent moisture content, whereas normal oatmeal has around 12 per cent - mean you pay for less water and more taste. The natural draught furnace that dries the oats is lit every day with the oat chaff and then kept hot with anthracite. The wheels of the mill are driven by water from the stream and as they turn the whole mill starts to grind and shake with sieves, wheels, drive belts all tied into the water power.

Donald monitors the whole operation with fierce, calm intensity. I ate oatcakes from his mill and they were nutty, crumbly and unbelievably delicious. The best. He does produce organic oats but to do so has to put an entire organic run through the mill which cannot be labelled organic, to remove any trace of inorganic oats contaminating the result. I believe this to be the root of the problem with organic food. We are too precious about it by far. I wholly support organic production and believe it to be the only sane way to produce food but we must not iconise it at the expense of common sense. On my travels all the best food was made by people passionate about a place and its produce. None of it was organic. It is too easy for middle-class, wealthy urbanites to sit on organic laurels. If we are to reach the people who matter, the ordinary consumer, then we must combine organic growing principles with a real sense of place and the local people that live there.

My series does not really address these issues full-on. As I said, it is not a food programme. But filming it confirmed a few things. The first is that the standard of food offered in most restaurants and hotels outside London is appalling. There is no excuse for this. It is dire and expensively dire at that. The second is that a generation has grown up without knowing what good food is. We all need re-educating. We need to constantly remind ourselves of the elementary fact that fresh, local, seasonal ingredients simply prepared make the best food.

Food supply businesses have conspired against this for the past 50 years. It is time to stop now. And the final thing was entirely positive: people everywhere are interesting and interested. The skill and passion is out there, plus the ingredients. We must question these ingredients. Whenever we sit down at a table to eat a meal we have paid for, it should be good. Anything less is unacceptable and we should always say so. Above all, we have to apply the same high standards of our home cooking to restaurant food, because the best of British food is inextricably connected to places and their people.