Creating one of the world's finest restaurants was just for starters. Now, Spanish chef Ferran Adrià has built a laboratory where he can really let his imagination run wild.

Within a former chapel, in an 18th-century palace in the heart of Barcelona's old city, Spain's most restless and creative chef is beginning his day, consulting his two lieutenants and reaching for the telephone. I have waited almost a year to reach this inner sanctum.

Within a former chapel, in an 18th-century palace in the heart of Barcelona's old city, Spain's most restless and creative chef is beginning his day, consulting his two lieutenants and reaching for the telephone. I have waited almost a year to reach this inner sanctum.

Ferran Adrià's three-Michelin-starred restaurant, El Bulli, three hours away near the French border, is already famous for offering one of the world's most radical gastronomic experiences. Strong men have wept after eating its 14-course set menu. Noodles made from jellied consommé, lobster gazpacho, Parmesan ice-cream, grilled strawberries, razorfish filled with coconut juice, tortilla reinvented and served as separate potato, onion and egg foams - these are a few of the 3,000 dishes Adrià has delivered to an increasingly fervent, cosmopolitan clientele.

Unusually for a Spanish chef, Adrià has no family tradition in cuisine, just raw talent. He was born in a humble suburb of Barcelona, 38 years ago. Assigned to the kitchens for his military service, Adrià was rapidly entrusted with official banquets, from the buying to cooking to keeping the accounts. He arrived at El Bulli when he was 22, and within eight months he was head chef. Soon after he arrived, the restaurant lost one of its two Michelin stars, but Adrià later recovered it, and was awarded a third in 1997.

The palace - an old aristocrat's residence, now being restored and divided up amongst small, mostly design-type businesses - is where Adrià has set up his new headquarters, and where he is now receiving the first visitors. Called El Taller (literally, "The Workshop") it is a type of laboratory, or design centre - in Barcelona it is a word architects use for their offices. Located a short walk away from the main market on Las Ramblas, El Taller comes complete with a library, a chapel/meeting room and a state-of-the-art kitchen. In the winter months, when El Bulli closes, this is where Adrià will lock himself away to invent. He says he'll never be able to create a better restaurant than El Bulli. The lab is a platform for a new concept which is still being formulated: the chef as pure thinker, an architect of new habits. It's a way of selling his ideas without leaving his own kitchen.

At 10 o'clock he still looks like he has just got out of bed. He dispatches the business of the day in short sharp bursts. But he somehow avoids being rude or abrupt. He always leaves a little pause for his interlocutor to catch up. When } I ask about the severe discipline at El Bulli, he fixes me with a wide-eyed stare. "This is not a game." The two young chefs lounging on the other side of the table, who have both been with Adrià for most of a decade, smile and adjourn. At his most serious, Adrià is disarming rather than frightening.

Adrià is also an excellent teacher who struggles to be understood. "Strange? Strangeness is a cultural problem," he says, explaining how he arrived at some of the more unusual dishes. "And - excuse me - we are very rational." At the moment, he is particularly proud of his hot jellies, which successfully subvert two customs: that soups are liquid, and jellies are cold. It took him a year and a half to perfect the technique. Just as I am beginning to feel like the star pupil of a mad professor, Adrià says he has to go. He is being interviewed on the radio. Then an idea occurs to him. I can come too and join in.

How to eat for 100 pesetas (35p) a head is the theme of the programme, hosted by a presenter well-known for his anarchic humour. That a meal at El Bulli starts at 13,500 pesetas, without wine, is part of the joke. Wafer-thin slithers of artichoke on top of hot pasta (the heat cooks the vegetable), deep-fried scampi legs (hard bits included) and beetroot chips are some of Adrià's suggestions, preceded by urgent advice on how to cut and fry properly. This is all delivered amid a running battle of wits with the debunking presenter and his sidekick. The presenter can't resist playing on Adrià's reputation for eccentricity. "One of these days there'll be a huge bang and Ferran will emerge from his lab with his hair frazzled and face blackened. Ha ha ha!"

At this point Adrià turns to me. "Tell them what the British think of Spanish cooking. Tell them what you told me." I have no choice. I repeat what I had said in the taxi. That, in general, the British think Spanish food is heavy, vegetable-free and eaten in huge long meals, or is a tapa, which we order 10 of to try and make a meal. Adrià is delighted by the shock of this revelation, which produces a stunned silence. It is the sort of effect he likes to provoke with his cooking: the unexpected opening up of a new vista, or the demolition of an unexamined opinion.

Back at the lab, the serious part of the day is about to begin. Adrià's younger brother, Albert, and fellow chef, Oriol, are already shopping in La Boquer'a, the market which, despite attracting tourists, is really a mecca for chefs, and is famed for having the best and most arcane products, if you know where to look.

At three o'clock, Adrià disconnects the phone, and the three chefs don their work clothes. A "script" has been drawn up. Pickled oysters, angel hair made from pumpkin drawn into fine strands, sweet cauliflower couscous, beetroot, kidneys, fresh sardines with sardine powder, frozen truffles, mushrooms in jelly. They don't necessarily stick to it, but it acts as a guide. The method is to start with good produce and a simple idea and investigate the possibilities. A quiet descends on the kitchen while they work.

"How do you want the sofrito?" Adrià asks his brother, chopping an onion. "Normal."

It may not be the most glamorous part of being a chef, but luckily for his fans, it is the part which Adrià likes best.