Move over Heston, the demon chef's here

A large tattoo on his right bicep announces Alvin Leung in Chinese as the "demon chef". He wears blue-tinted glasses with arms of carved wood and sterling silver hinges. 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," Alvin Leung says. "I want to give you maximum excitement so that if you go one more step, you fall off the edge."

Leung 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 on the edge. 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 the condom dish, 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."

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," Leung 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".

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 a flake of gold leaf. "The bird's nest is very important in Chinese culture," he says. "It stands for family and unity."

Food barely featured in Leung's childhood. "I can't remember a dish my mother made that to me was pleasant," he says. Forced to cook for himself if he wanted to eat well, he says his rebellious personality inspired him to experiment. During a career in Hong Kong designing music studios – he studied acoustic engineering at South Bank University in London – he amazed friends at dinner parties with his out-there cuisine. When a tiny restaurant became available, Leung seized it.

So 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. 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. "I'm not cheap but I'm not unaffordable," he says. "I've been around to top restaurants here and they're quite full."