Here comes the demon chef: Is London ready for Alvin Leung's 'x-treme Chinese cuisine'?

A large tattoo on his right bicep announces Alvin Leung in Chinese as the "demon chef". He wears £1,000, blue-tinted glasses with arms of carved wood and sterling silver hinges, but has perfect vision. He smokes cigars and wears earrings. His chef's whites are always black and one of his signature dishes resembles a used condom discarded on a beach of sand made of mushrooms.

"I want to take you to the border of comfort," Leung says, spreading his arms. "I want to give you maximum excitement so that if you go one more step, you fall off the edge. It's like a bungee jump. I want your nose to touch the ground so that if you go one more inch your brains are gonna be all over the place."

If you did lose your brains, Leung would probably cook them. He is unusual even by the standards of an industry in which mavericks thrive. The British-born son of a mother who could not cook, he worked for 20 years as an engineer. Then, in 2002, and without any training, he opened Bo Innovation, a small restaurant in Hong Kong. Six years later, he won two Michelin stars, a feat achieved by only two self-taught chefs (the other one is Heston Blumenthal).

Now, Leung, who is 51, is returning to the city of his birth to open a restaurant in Mayfair, where he is overseeing the final fortnight before the first customers arrive. He is frantic. Until he learns if London is ready for his cooking, which he calls "X-treme Chinese", he's the one dangling from a cord. Much of the £1.5m being thrown between these walls is his money. "If this fails, I'll just be another statistic," he says. "I have to succeed."

The condom dish, called "Sex on the Beach", won't be on the menu but anyone who dares to take the unsavoury leap may order it. Its birth two years ago reveals much about how Leung can be inspired but then warp his ideas to confound expectations even in a world that has become used to fantasies of "molecular gastronomists". It started with the sand.

"I was messing around with ways to make soil," he says, while electricians, builders and his personal staff circle him. "Everybody's doing the garden, you seen that? They make edible soil and put nice things on it. I made something with shiitake mushrooms that looked like sand and then, in my little deformed mind, I said, I gotta do a complete U-turn here."

It took Leung days to perfect his technique. He dips a cigar former into a viscous pink liquid made of tapioca and yams to create a translucent sheath, into which he injects a white mixture of honey and Yunnan ham. He then lays the edible prophylactic on to his mushroom sand.

"Then I thought, if you exploit this financially, people are gonna criticise you. Look what this arsehole is doing with food. To "sneak it through", Leung donates proceeds from condoms, which will come with an £8 supplement in London, to the Elton John Aids Foundation. They have raised more than £40,000 so far. "Aids awareness is probably most fitting," Leung adds. "I don't think you could do that dish to save the whales."

Leung has been called the Heston of Hong Kong after Blumenthal, who went on to win a third Michelin star at the Fat Duck at Bray in Berkshire. But, he says, "I can't compare myself to Heston. He's too big. But he's inspiring and I feel like he's definitely paved a path in England for me to walk on." The tattoos and jewellery have also lead media in Hong Kong to call Leung the "rock'n'roll" chef. "They were calling my food modern Chinese; molecular Chinese. I don't like being labelled so I decided to label myself," he says. The Demon Chef and X-treme Chinese was born and suited the born showman in Leung.

The chef has devised several set menus for Bo London, which will seat up to 50 diners on a side street near Oxford Circus. His 12-course Ode to Britain costs £98 and is a bold subversion of traditional British fare with Chinese characteristics. The "toad" in the hole is a frog's leg, and his steak and kidney pudding is in the form of a xiao long bao, or Chinese steamed bun. A savoury "trip-fle" includes tripe, mussel custard and lychee cream.

"The extreme element just means a different interpretation of Chinese food," he says. "People either think of cheap, greasy, bad service, or if they think of exotic Chinese food they see shark fins, monkey brains or tiger penises. That's not me. Everything I do is about Chinese culture. My dishes have to symbolise something because they taste better when people understand."

Leung has agreed to prepare the menu's first course, called "Bed and Breakfast" for me. He barks after his assistant for his glasses and black uniform, which is embroidered with "Maverick Chef", the name of Leung's TV show (each episode sees him guided through the cuisine of a new Asian city by an attractive local guide, for whom Leung then prepares his own dinner).

Ready, Leung lowers into boiling oil a smoked quail's egg which has been set in a ring of putty-like taro paste. The taro immediately puffs up to create a nest around the egg. He slides it onto a specially commissioned chrome tree before adding Chinese caviar and, using tweezers, a flake of gold leaf. "The bird's nest is very important in Chinese culture," he says. "It stands for family and unity."

Leung was born in London to Chinese parents. His father's work as an engineer also took the family to Toronto, but Alvin, the eldest of four, returned to the capital to study acoustic engineering and environmental science at South Bank University. Food barely featured in his childhood. "I can't remember a dish my mother made that to me was pleasant," he says. "To this day I have a phobia of instant noodles." Forced to cook for himself if he wanted to eat well, Leung says his rebellious personality inspired him to experiment.

"I was the black sheep who did everything that was opposite," he says. At aged 10, he was adding curry powder to spaghetti and later, during a career in Hong Kong designing music studios, he amazed friends at dinner parties with his out-there cuisine. When a tiny restaurant became available, Leung seized it and launched Bo Innovation in 2003.

Leung used his lack of training to break rules he didn't know existed, but his cooking was not immediately embraced by everyone. Despite excited local reviews, the chef was burned in 2005 by a review in the International Herald Tribune. Patricia Wells, a food writer, said comparisons to Ferran Adrià's now-closed El Bulli restaurant in Spain were "a bit like saying that Kentucky Fried Chicken is on par with a restaurant run by Joël Robuchon." "She totally, what do you say... destroyed me," Leung recalls. "But every single criticism is a learning experience, whether or not you think it's true.

"You have to accept it and accept it with grace. This is the Chinese way."

Leung says he has grown up a lot since, but is he nervous about the response of London's critics? "I've got a big bag of money," he jokes. "No, I read what they write about other chefs. I've done my research. Chinese are famous for gambling but I'm a businessman. This is not a gamble." Leung is also confident customers will pay for his food. His 15-course chef's menu will cost £138, not including drinks, while dim sum, which will be available at a bar between services, start from £6 a mouthful. "I'm not cheap but I'm not unaffordable," he says. "I've been around to top restaurants here and they're quite full."

Before he gets back to preparing his restaurant, Leung wants to make his signature cocktail, a lemon and lime sour made with egg whites and baijiu, China's fearsome white liquor. He blends the ingredients with ice before pouring the mixture into a bespoke porcelain cup modelled on an ancient Chinese wine vessel. His designer has perfected the profile of the spout so that when it is tipped towards the mouth, the liquid builds up threateningly in the cup, as if it might suddenly cascade over the lip. Then, at the optimal angle, relief comes as the spout releases instead a perfect trickle. Like his food, it's dangerously delicious.