DAVE Myers is a shadow of his former self – literally – when we speak.

Last time I interviewed him he was several stone heavier. Now he is a pert 14 and a half.

He might be even slimmer this time next week, having cooked for thousands as the Hairy Bikers become Cornbury Festival’s headline chefs this weekend.

Not ones to do things by halves, Dave and his fellow partner in crime/TV presenter Si King, are preparing to cook the whole feast in wood burning ovens.

From roast cauliflower with spiced anchovy sauce to wood fried crispy skinned sea bream with sauce vierge, potatoes a lo pobre, with fennel, capers, garlic, sherry vinegar and oregano, and warm spiced rice pudding with wood roast peach compote, they are pulling out all the stops.

“We have committed to three sittings a day, for three days, and will introduce each meal with a little speech to explain the food and where it comes from,” Dave says.

So why now? After all festivals and celebrity chefs are hardly a new concept?

“Yes there are lots of other food festivals, but I suppose we were just waiting to get it right. We’ve been thinking about doing something for years but didn’t want to go in half cocked,” Dave explains.

“And then we came up with the wood fired restaurant concept. It’s a massive undertaking but we have eight chefs with us and some beautiful menus so we can’t wait.

“When we were given the go-ahead we knew the wood burning ovens would be perfect because we could think big – four starters, big communal tables. It meant we could cook chicken, fish and vegetables. It gave the whole experience an extra dimension. We weren’t going to get away with serving dirty burgers with some bone marrow, but neither could we have done it half-hearted.

“So instead it will be like having dinner at my house where everyone eats outside, so please God let the weather be good,” he smiles.

It’s rare for the duo to make such a public appearances. Yes, a few years ago they did a live theatre tour but then their popularity surged again with the success of their baking and then dieting TV shows, and they were back filming every second of the day.

“This will be the first time we have taken time out for a long time,” Dave accedes. “But the founder Hugh Phillimore puts his heart and soul into making Cornbury work, so we are very excited. We just want to pitch in and have a good time. We are bringing our families and I think Si is playing with his band.”

In what capacity? “He was in a band for years, still is actually – Little Moscow. They were all at school together and they are playing on Cornbury’s Campsite Stage on Saturday night when everyone else is finished, so we are all excited about that.”

As for Dave his main concern is the temperature: “Cooking in wood ovens in that heat will be interesting, but it means you can use really different ingredients like cauliflower with lemons, olive oil and spices. The ovens mean it retains its crispiness while staying sweet.”

It’s always been about the food for Dave Myer, even when he was a prosthetics make-up artist, cooking for the crews, always one of the gang, spreading the love.

And yet after four series of The Hairy Bikers has his interest started to wane?

“It’s a choice being on TV. And it’s what we do,” he says in that cheery voice of his.

“We film 200 days a year and travel the rest. It’s pretty unsustainable granted. And we also bring out a book a year which is almost an entirely separate thing, so it’s not like we just concentrate on the TV work. But then neither are we doing 100 covers a night.”

And what of their svelte figures. Is it a phase, a clever way of selling more books? Can they keep the weight off?

“Yes, because we were morbidly obese and we had to sort ourselves out. We were on tablets because we were so fat and were heading to an early grave,” he says earnestly.

“I remember cooking a huge chocolate cake in a square in Turin in 90C heat and having to take blood pressure tablets, and just realised that it wasn’t sustainable. But we had to do it together.”

The Hairy Bikers did just that, reinventing themselves at the same time as they shed seven stone between them.

“At first we wondered if there was a quick fix like a health farm or an aerobics class. But we were so unfit. We realised we needed to go on a diet instead which is really old-fashioned. It meant no more pies and rewriting all our recipes.

“So we just reworked them to make them more healthy, quick and simple with fewer ingredients rather than sticking post-it notes all over the fridge.

“But people aren’t stupid, the recipes have to work.”

As for Dave, where does he spend any down time? Either in Kent or France (he has homes in both). I have polytunnels and grow vegetables.

“But I don’t need much. I like doing things like Cornbury. I’m looking forward to it. I hope it’s the start of something new.”

Katherine MacAlister