The Tao of Yau

'I am going to be ordained on 4 July. I will stay in the temple for six weeks,' he says in his singsong Chinese accent. Once I've stopped choking on my daikon pickle, I'm free to wonder why this purveyor of earthly pleasures wishes to closet himself away and follow a distinctly Spartan regime involving a shaved head, one vegetarian meal a day, and meditation from 4am? 'I want to be much more intuitive, both spiritually and creatively,' he explains. 'I'm not a fanatic – my search is more intellectual. And I truly believe in the power of meditation.' He already meditates for three hours a day, regarding it as a vital business tool. 'Meditation is so powerful. It allows me to be much more creative, to access my feminine side.'

We are having lunch at Sake No Hana, a minimalist temple to Japanese gastronomy in St James's which Yau owns in partnership with Evgeny Lebedev (chairman of Evening Standard Ltd). Despite just getting off a flight from Hong Kong, Yau, 47, looks extremely good. His skin is unlined and lightly tanned, and he is wearing a crisp white Dolce & Gabbana shirt, purple Ozwald Boateng jacket and jeans. Around one wrist is a string of beads. 'It's something to do with feng shui,' he explains, before waving away fig tempura and raw scallop slivers. 'I'm not eating,' he says, shaking a packet of vitamin C powder into a glass of water. 'I'm about to do a liver cleanse.'

Sake No Hana recently closed for six weeks for a major refurbishment. The (not universally loved) tatami floor mats have gone, a new sushi counter gives a buzz to the previously austere first-floor room, and the menu has been redesigned by a new head chef, Daisuke Hayashi, who trained under Yoshihiro Murata, proprietor of the renowned Kikunoi restaurant in Kyoto.

So far, it all seems to be money well spent. The place hasn't officially reopened yet, but on a rainy Tuesday lunchtime it's packed.

Settling back in his chair, Yau slowly surveys the room. This is the first time he's seen it since the new tables have been installed, and he's a famously nit-picking perfectionist. 'It's OK,' he says finally, with a nod.

But recently Yau has been busy winding up his other London operations. In 2008, he sold Hakkasan and Yauatcha for £30.5 million to Tasameem, the property arm of the Abu Dhabi Investment Authority. In January, he sold the Busaba Eathai chain to Phoenix Equity Partners for £21.5 million and is no longer involved with the mini noodle chain Cha Cha Moon.

He retains only his interests in Sake No Hana and Princi, the Milanese bakery on Wardour Street. And once the monastic training is complete, he will turn his attentions to a new Hong Kong venture.

'It's near to impossible now to get debt finance from the banks to open new businesses here,' he says. 'In Hong Kong and China they're still lending. And I prefer to operate in conditions where the country is still growing. I'm not that young any more so I'd prefer to have my next big idea somewhere where I can get the money and where people are still spending.' He's also rather unhappy about the prospect of paying 50 per cent income tax. 'In Hong Kong, it's 15 per cent! And no VAT'

But desolate diners should not be tempted to commit hara-kiri just yet. Before Yau leaves, he will bestow a couple of new establishments on the capital. The first will be a high-end Chinese restaurant. 'I'd like to leave London with a spiritual home,' he explains. The restaurant is intended to rival Hakkasan, once the jewel in his crown, in which he now admits he's lost all interest. 'It's better to detach yourself emotionally when you sell,' he explains, 'otherwise every change affects you. And it's like any relationship – once you finish it, you see all the faults.'

The other restaurant project is at the opposite end of the scale: a small Turkish joint. London is already well supplied with these, but such is Yau's Midas touch when it comes to food that you can bet that they'll be queueing around the block 'Going to Hong Kong is like the final part of my journey,' he goes on, 'and I feel that going through this process will allow me to move on from where I've been and what I've been doing to the other side.'

There is certainly a symmetry to his move. Yau came from Hong Kong at the age of 12, in 1975, to King's Lynn where his parents had a Chinese restaurant. His father, Yau Cheung Wo, was a tailor who'd come to seek his fortune and discovered that running a restaurant was one of the few options open to immigrants from China. 'I really hated the food business for years because of what my parents went through.' As part of the only non-white family in town, young Alan was subject to bullying, getting into fights once or twice a week. Inevitably he started working in the family business and even now he regrets that he didn't become a fashion designer or a photographer.

Still, few of his compatriots have made such a spectacular success of necessity. Behind the takeaway counter, he started to think about how to change the restaurant industry. After studying politics and philo-sophy at university in London, he opened his own Chinese takeaway in Peterborough with help from his father, and made back the £50,000 investment in six months. But, he sighs, 'I should have come to London earlier. I think my learning curve would have been a lot faster.' Instead, he returned to Hong Kong to work at a McDonald's for three months, to nose out the secrets of a successful fast-food operation. Yau's earliest restaurant plan was to create a Chinese fast- food chain. 'I spent £16,000 with a consultant who used to be chairman of KFC. My brief was to look into the viability of a Chinese McDonald's, but it didn't work out.'

Instead, he came up with the concept of Wagamama, which he opened in Bloomsbury in 1992 when he was 29 and had been living in London for just a year. Wagamama, with its communal tables, speedy service and giant bowls of Japanese noodles slurped in a minimalist basement designed by John Pawson, was a truly new idea and London couldn't get enough of it.

But the private equity people Yau brought in to fund the chain's expansion squeezed him out in 1997 and then took it global. Branches of Wagamama are hard to avoid nowadays, which makes it something of an achievement for Yau only to have eaten there once in the intervening 12 years, in Sydney. Did he enjoy it? 'No. But you might think I would say that.'

Anyway, just as he is now returning to his roots in Hong Kong, he is also returning to his earliest food concept – that Chinese McDonald's idea. 'The core working criteria are a single product, like burgers for McDonald's, a portability and de-skilling, so you can pay people the minimum wage to reproduce it. The blueprint is everything. In a Michelin-starred restaurant, if you make a mistake planning the kitchen it's fine because your £100,000-a-year chef is so skilled, they can overcome any deficiency. With fast food it's much harder.'

He hopes to have the concept, which he still won't discuss, up and running by 2011 in Hong Kong. His ultimate aim is, he says, 'world domination'. 'A restaurant like Hakkasan is like an Apple Power Mac – it's wonderful, sexy, loved by the creative industry, but at the end of the day, it only represents two per cent of the market. What makes Apple renowned is the iPod, which is low rent but touches everyone as a mass-market product. I see my fast food as an iPod.'

Money isn't what motivates Yau, who is prepared to gamble his fortune on this idea: 'Because of my poor background, I really don't have a problem if one of my ideas consumes most of my wealth. To me, that is part and parcel of it. I enjoy the process.' He's already planning a hotel, and would like to branch out into a completely different business. 'I would like to think that this would be the last of my restaurant ideas,' he says. Then a faraway gleam comes to his eyes. 'Although I'd love to do an English teahouse in Hong Kong, like Bettys in Harrogate, with scones and tea and shepherd's pie. That would be funny, for a Chinese man to do that' I suspect whatever continent he lives on, Alan Yau will be influencing Londoners' tastebuds for some time.

Sake No Hana, 23 St James's Street, SW1
(020 7925 8988; sakenohana.com)