Peter Gordon - founder of the celebrated Sugar Club - is back, with a new vision of fusion in a very cool neighbourhood

I know it's been a few months since I last visited a serious restaurant, but can everything really have changed this much? What the hell are jicama and wattleseed, wing-beans and chioca? Have I been through some kind of Rip Van Winkle hibernation, and woken up years into the future?

Relax, it's just Peter Gordon, pioneer of "fusion" cooking, showing us what he's been doing on his holidays. The Providores is the New Zealander's first new venture since late 1999, when he and co-head chef Anna Hansen left The Sugar Club. First in Notting Hill and later in Soho, The Sugar Club was the restaurant which introduced Britain to the Pacific Rim style, with its adventurous combinations of Asian and European elements.

Gordon and Hansen have parted from their former backers, and together with their respective partners are now running their own show, in the grooviest part of central London. Marylebone High Street used to be a dusty parade of charity shops and orthopaedic showrooms. Now it forms the heart of newly fashionable "Marylebone Village", a zone whose real-estate renaissance was jump-started by a Terence Conran development, and confirmed by the recent arrival of Mr and Mrs Guy Ritchie.

Where once there were only a couple of old-fashioned restaurants, the High Street now boasts several very good modern ones, from the atmospheric Italian, Ibla, to Conran's Michelin-starred Orrery. The area tends to be quite busy during the day, but fairly quiet at night, and it's to cater for the daytime crowd that Gordon and co have set up the informal downstairs café – the Tapa Room. It serves an all-day menu of light dishes, starting with what must be the most evolved breakfasts in town (you don't just get plain old omelette here, but sweet potato and smoked paprika tortilla with roast peach chutney, ruby chard and Argan oil vinaigrette.)

The Providores upstairs is the serious restaurant part. Plainly decorated with white walls and chocolate leather seating, the room lacks the atmosphere of the original Sugar Club, and with its disproportionately tall, arched windows and suspended ceiling, gives the impression of having been carved out of a much larger space. The dozen or so tables are crammed together, so that on a clammy night, with the air conditioning making little impact, we felt in serious danger of developing economy-class syndrome.

The evening was planned as a birthday treat for my friend Sharon. But our proximity to our neighbours meant that as she unwrapped her gift (a fetching twinset), the woman at the next table felt obliged to get involved. She was practically wearing Sharon's outfit by the time Clare and Alison arrived to complete the party.

The menu is fairly short, but hardly to the point; each ingredient gets a separate billing, with provenance where appropriate. The most expensive starter is smoked foie gras on bruschetta at £9.80, the cheapest a chilled tomato, chilli and ginger soup with Argan oil at £3.80 (sadly, there was no room on the menu for the full history of Argan oil, which is pressed from the stones of fruit that has passed through the digestive systems of Moroccan goats. Maybe it's just as well.)

My meal got off to a heavy start with a sourdough roll, which was spiked with raw-tasting garlic and had the texture and heft of a saturated nappy (no prizes for guessing how I've spent the last few months). My palate was sent reeling, and the delicate combinations of flavours which followed may well have suffered as a result. Luckily, my starter was a fairly robust number; one of Peter Gordon's trademark dishes, a laksa, or spicy Malaysian soup.

It was made with coconut milk and crisply fried shallots, and garnished with tendrils of char-grilled baby octopus, a deep-fried quail's egg and delicately smoky green-tea noodles. Like many of the dishes on the menu, it read like some kind of absurd, William Burroughs-style cut-up, but tasted like heaven.

Plantain and cassava fritters were surprisingly light and herby, given the starchiness of those vegetables, and served with a superbly complex tamarind chutney. A plate of Teruel jamon, fresh figs and petit Lucque olives was less distinguished – the figs were over-chilled, and the olives underpowered ("but then, they're very young olives", Clare announced with quite surprising confidence.) Sharon was also disappointed with her salad of fennel and roast tomatoes, deeming it cold and watery. "The croutons are really nice, though," she quavered, in an attempt to sound positive.

Main courses, like the starters, are notably healthy, containing hardly any dairy or heavy carbs. In fact, this is just the sort of food that Madonna might pick at before donning her chaps and stetson for some stadium gig. The Japanese influence seems stronger than it did at The Sugar Club; edamame, or fresh baby soya beans, garnish several of the dishes, and miso and green tea are among the favoured flavourings.

Roast halibut steak – far juicier than that meaty fish can often be – is rendered even more succulent by an aromatic dressing of yuzu, a Japanese citrus fruit. Slices of pink duck breast combine surprisingly well with sweetly roasted yam. A humble baked aubergine is transformed by miso and sake into a complicated taste sensation, and served with a taro rosti , which sounds like it should be a Hollywood starlet – "click HERE to see nude pics of Taro Rosti..." – but tasted like sophisticated comfort food. Also pleasingly emollient was a side order of sweet potato and miso mash, a vividly orange purée, fragrant with nutmeg. "You could take this back for the baby," Sharon observed, as we spooned it down.

The Japanese tendency continued into the puddings, where a vanilla and mascarpone tart came topped with yuzu roast plums. Panacotta was flavoured with green tea, and shuddered beneath a luminous lychee jelly. Clove meringue was an innovation too far for my taste, reminding me as it did of bread sauce, but the others loved it.

I didn't go to the original Sugar Club often enough to know whether The Providores represents a change of direction for Gordon and Hansen, but I suspect that it's simply a confident progression. Our meal was prepared and presented with fantastic care, and served with smiles by the knowledgeable, mainly female front-of-house team, who didn't allow the heat and bustle to dent their good humour, even when Clare inadvertently broke the no-smoking rule. With two bottles of £24 Sauvignon from a list which is particularly strong on New Zealand wines, our bill came to around £40 a head. Maybe a little cheap for Madonna, but then she probably wouldn't enjoy such enforced interaction with her fellow Londoners, anyway.

The Providores, 109 Marylebone High Street, London W1 (020-7935 6175). Daily 12-3pm, 6-10.45pm. All cards accepted. Limited disabled access. Smoking downstairs only