It had been two years since Sophie Dahl had, rather to her dismay, made a name for herself as the "large" model who was going to smash the fashion industry's obsession with skinniness. She'd quietly begun regular visits to the gym -
"I didn't really want anyone to know... it was all a bit surreptitious, as if I were having an affair" - when her mobile phone rang. It was her personal trainer calling to leave a message about her next session.
If Dahl was already uncomfortable with her secretive new regime, she felt even more vulnerable once her gym teacher had put down the phone - or thought he had. Unfortunately he hadn't hung up properly, and the voicemail was rather more revealing than he or Dahl would have hoped. The trainer turned to his companion and said: "So you know who that was, right? She says that one day she wants to have a body like Cindy Crawford. Have you seen her, poor cow? If we were ever to make a workout video it would be called Loud and Lumpy. Biggest arse I've ever seen. Big everywhere, actually."
Eleven years on, the incident makes her smile (it didn't at the time). "Listen," she says. "People talk shit about each other all the time. It's really unfortunate that people bitch - and sadly I heard. So I rang him back and said that now I felt uncomfortable and I'd always feel that he was silently judging me. I told him: 'I don't want to feel like that. Particularly not with someone I'm paying.'"
The training sessions came to a swift end.
Dahl, now 31, never chose to be known for her size but soon grew to realise that the industry she'd entered was not going to let her forget that when she was discovered at 18 she was not a standard-issue supermodel: "I had enormous tits, an even bigger arse, and a perfectly round face with plump, smiling cheeks."
As has been publicly documented every step of the way, Dahl is no longer enormous, big or even plump. Where once she was a size 14 - not, frankly, large at all in the real, non-fashion world - the woman sitting across from me eating lunch (yes, eating!) in her favourite Notting Hill hotel is now a size 10. She is still beautiful. Huge greenish eyes, a wide and warm smile, friendly, open gestures, long legs curled underneath her. A giant diamond engagement ring (she is engaged to the singer Jamie Cullum) sparkles in the light.
And far from renouncing food, she's just written a cookbook. How many fashion models would or could do that? Miss Dahl's Voluptuous Delights is a handsome book - part recipe collection, part food memoir - that makes you feel good about food in a way no high-concept Vogue cover image could. Beautifully shot and well-written, this is clearly not a piece of "celeb merchandising" but a thoughtful book by an enthusiastic food fan.
The use of the word "voluptuous", which chased Dahl around in her larger days, is, she says, "camp and tongue-in-cheek" rather than a deliberate taunt. But it's also a useful marketing tool to remind everyone why they remember Sophie Dahl.
Writing a cookbook is a quirky career development for a model, I suggest. We're unlikely to find out Kate Moss's recipe for soufflé, are we?
She laughs. "I don't know her soufflé recipe. She might have a jolly good one up her sleeve, you never know. I just know mine. But part of the joy in writing this book is saying to people that just because one has modelled doesn't mean one doesn't eat."
Hold on a second. Actually, very often it means precisely that, I say. Dahl refuses to accept that. I rephrase the question: when did you realise that you were different from a lot of other models? "I didn't know I was different. It wasn't until the wave of commentary began that I thought: oh Christ, I am."
That might have made itself apparent when, as she describes in the book, she found herself on photographic shoots surrounded by the stick-thin and the only woman unable to fasten the clothes that had been supplied. Didn't you, I ask, feel humiliated by that?
No, "because I had quite a strong sense of self. And I don't know whether you've ever seen those dresses, but they're quite tiny." She reconsiders. "Well, it would be disingenuous to say there weren't moments where I thought: 'God I wish I fitted into that dress', but I didn't go off and starve myself in order to get into them."
In the book, she writes: "In my time, I have been both as round as a Rubens and a little slip-shadow of a creature." She documents the food phases throughout her life. Making cakes in her grandmother's kitchen. Stuffing down bagels in Golders Green. A weird raw-food chapter in New York. Having to pretend she had someone over for dinner when she ordered takeaways so that she could justify buying twice as much dinner as she needed.
So what about today? "I eat very simple food, really. A lot of it tending towards nursery food. I love cooking fish pies. I like making roast chicken, cauliflower cheese, those sorts of moreish things. And I often do breakfast food for supper: frittatas, toast and a Spanish omelette. Easy, simple, quick things." She splits cooking duties with Jamie, who "is a genuinely good cook ... he does a lot of Nigel Slater recipes. His grandparents were Burmese on his mother's side, so he makes a lot of sort of Burmese curries."
I'm in the perfect place to find out about her relationship with food now. It's lunchtime. The menus are in front of us. I go for the fish pie and a glass of white wine. Dahl's choice: warm peppered goat's cheese with a red leaf salad and orange dressing. Cheese? That's scarcely the lo-cal option. I find her choice cheering. And when the food arrives, it looks suitably fattening. Hurrah!
So - abortive gym sessions apart - how does she explain her change in shape? "My mother, all of her sisters and my siblings all went through a stage from the age of about 15 to 19 where they widened and then lengthened. Had I not been modelling, that would have been a phase that was in a family photo album rather than in Vogue."
Yes, she got letters from large women saying congratulations, how thrilled they were to see somebody they felt represented them, when she was larger. But she didn't feel she'd let them down when she lost weight, "because I was just getting on with my life, and one's body shouldn't be dictated by projections of other people". Other women don't have the right to dictate what she looks like, just because "in one particular incarnation I made them feel better about themselves".
Was the whole "big model" thing, I ask, foisted upon her? "It wasn't foisted upon me because I was also complicit in it, but I fitted a niche for that time. When I signed a modelling contract with Storm at the age of 18, I didn't think: 'I'm going to go out there [as a large woman] and show them ...' At 18 do you really think about things that much?"
In fact, there were probably other things on her mind. Dahl's upbringing was anything but stable. She went to 10 schools and lived in 17 homes, with a mother - the writer Tessa Dahl - who struggled with a drug problem, alcoholism and depression (and once slept with one of Sophie's friends). But she didn't realise how unusual her experience was - though that may have become apparent by the time she started dating Mick Jagger, about whom she has never spoken publicly.
Her grandfather, the children's author Roald Dahl, injected steadiness into a chaotic life. Though he died when she was 13, Dahl remembers visits to his Buckinghamshire house and his vast appreciation of "chocolate, borscht and burgundy". He kept an old gypsy caravan in his garden which the children used as a playhouse. "It was brutally uncomfortable and really cold, but I would stay in there with my friends and so we'd have midnight feasts of chocolate in bed. Then in the morning we'd appear in the house and he'd make us all breakfast." Marmalade on toast. "He was wonderful. Really wonderful."
We come towards the end of our lunch. "I think it would be a bit miserable going out with somebody who was totally uninterested in food," says Dahl.
Has that ever happened? "I've always gone out with people who are quite greedy." Can Mick Jagger cook? A frosty glare - the first and last of our interview. "I'm not getting into that with you, I'm afraid." How annoying, if unsurprising. I fear that, like Kate Moss's soufflés, we'll be waiting a long time for Mick's lemon drizzle cake.
Warm relations are restored, but the delicious Dahl needs to rush off. Mwah, mwah and she's gone, leaving me alone in the restaurant.
The plate that had been in front of her, so full of calories when it arrived, is still full of goat's cheese (and calories). She's eaten precisely half of the food that was served to her.
It'd be shameful to let it go to waste. I furtively swap plates and finish the food for her. My modelling career can wait.
• Miss Dahl's Voluptuous Delights is published by HarperCollins, £18.99. To order a copy for £16.99 with free UKp&p go to observer.co.uk/bookshop or call 0330 333 6847
Broad bean salad with pecorino and asparagus
Serves 2
180g baby asparagus tips
150g fresh or frozen baby broad beans, skins removed
small handful fresh mint, finely chopped
3 tbs good-quality olive oil
salt and pepper
50g pecorino cheese, crumbled
Put the asparagus in a pan of boiling salted water and boil for 2-3 minutes. Drain and rinse under cold water.
Place the beans and asparagus tips in a small salad bowl and add the mint. Pour on the olive oil and add some salt and pepper. Add the cheese. Serve.
Breakfast burrito
Serves 2
1 tbs olive oil
2 spring onions, white part only, finely chopped
1 tsp dried red chilli flakes
90g chopped tomatoes
4 eggs
50g cheddar
2 tortillas
a little fresh chopped parsley
First, heat the olive oil in a pan. Add the spring onions, chilli and tomatoes and stir for a few minutes. Take off the heat and put to one side. Scramble the eggs, adding the cheese at the last minute. Stir in the chilli tomato mixture and season.
In a non-stick pan, heat the tortillas one after the other, for about 30 seconds each side. Put flat on a plate and spoon on the egg mixture, with the parsley, and roll them up.
Clover's Carnation milk jelly
1 packet strawberry jelly
125ml cup hot water
1 can evaporated milk
Slices of strawberry, swirls of cream and curls of chocolate to decorate (optional)
Dissolve the jelly in the hot water. When the mixture is cool, whisk in the evaporated milk until the mixture is thick and frothy. Leave it to set for at least two hours. Cover the jelly with strawberry slices, swirls of cream and curls of grated chocolate, if you wish - the camper the better, really.
Blueberry strawberry smoothie
155g frozen blueberries
200g frozen strawberries
1 scoop protein powder
250ml unsweetened soya milk
agave syrup or honey to taste
peanut butter (optional)
Whack it all in the blender, adding water if you want it slightly thinner. I like smoothies to be like milkshakes. This is also totally divine with a tablespoon of peanut butter added.
Beetroot soup
Serves 4
6 medium-sized beetroots
5 spring onions, white parts only
olive oil
1.5 litres vegetable or chicken stock
shot of vodka
juice of ½ lemon
2 tbs crème fraîche
salt and pepper
good handful of dill
chopped hardboiled egg, to serve
Wash and trim the stalky bits of the beetroot.
Sweat the onions in a pan with some olive oil on a low heat until they are translucent. Then add some stock to the onions and leave on a low heat to warm.
In another pan, cover the beetroot with water, bring to the boil, then reduce the heat and simmer for about 30 minutes until the beetroot is tender. Drain, and when cool enough to handle, peel off the skins and cut the beetroot up into rough chunks.
Put the beetroot into a blender with the onion stock and pureé until smooth. Add the shot of vodka, lemon juice and crème fraîche, season and give the mixture another whizz in the blender.
You can serve this hot or cold. Either way, serve with the chopped dill on top, a swirl more of crème fraîche and some chopped hardboiled egg if you feel like it.