When worlds collide

The New World comes together with the old at Osia, where Australian flair meets Japanese precision and London prices.

Given the number of Australian chefs working in London, including the masterly David Thompson of Nahm and Shane Osborn of Pied à Terre, it's astonishing that there isn't a single listing for Australian food in the exhaustive Time Out Eating and Drinking guide. There's a cluster of Argentinian places, an Alsatian or two, and even an Armenian entry. But not a solitary restaurant to represent one of the world's most exciting and vibrant food cultures.

So the arrival of an ambitious Australian restaurant in handsome premises near Piccadilly Circus is potentially a cause for celebration. Osia's name presumably indicates the union of Oz and Asia, but the USP here isn't fusion food. Instead, it aims to marry the finest British produce with imported Australian ingredients, to create the kind of bold, simple flavours that make dining in Sydney such a delight. Chef and co-proprietor Scott Webster has a globetrotting CV, but has latterly been working as a roving ambassador for Australian food (banish thoughts of Sir Les Patterson, for fear of losing your appetite).

In Haymarket's Glitter Gulch of flyblown steakhouses and chain bars, Osia is an oasis of sophisticated cool. A beautifully proportioned dining room has been sprung from beneath the blonde-wood panelling of what used to be a branch of Café Flo, and at the rear, there's a secretive, sexy bar – more Manhattan than Sydney. Both rooms combine sweeping, organic lines with solid patrician textures, and the air is heavy with the smell of wood and leather, like the interior of a new Jaguar.

The New Yorkish impression created by the bar is reinforced by the selection of seafood cocktails and ceviches that appear on the menu alongside the hot appetisers. Served in chubby Martini glasses, these dishes sound showy – we tried crab cocktail with minted cucumber threads and flying-fish roe, and langoustine cocktail with buckwheat noodles and ginger soy dressing – but really pack a punch, assembling first-rate ingredients with as much attention to texture as to taste.

Even better was the hot starter: skewered ocean prawns, deep-fried in crunchy kunafa pastry (a fibrous Middle Eastern batter with a Shredded Wheat-like texture), with wasabi-flavoured mayonnaise.

Main courses were equally fresh and exciting. In an inspired take on the classic Italian vitello tonnato, a warm fillet of lightly cooked veal was partnered with creamed tuna, and a hot walnut sauce. Webster's classical training showed in a dish of pan-fried halibut with precisely cooked leeks, pumpkin and parsnips, which wouldn't have been out of place in a French restaurant (apart from the wild lime sauce, that is).

Osia's seared tuna salad was also a dish of rare delight, the loin sliced Oriental-style into thick ruby-red sections, and dusted with sesame seeds. The etiolated, sci-fi appearance of accompanying enoki mushrooms startled their recipient, The Independent's film critic Anthony Quinn, a notoriously timid eater. "What are they? They look like spawn!" he yelped. And he wouldn't so much as glance at our side order of fried green tomatoes. "I don't need to eat them. I've seen the film. That was bad enough." He had a point, actually; the slices of sour, sharp fruit encased in crisp batter didn't add up to much more than an interesting exercise in contrasts.

Our other side dishes, including silky mashed kumara (a New Zealand variety of sweet potato), were slick with butter, which seemed at odds with the healthy Asian lightness of the rest of the meal. No complaints, though, about the buttery Tuatara Bay Sauvignon Blanc (£20), selected from a predominantly New World list.

We couldn't leave without seeing what Osia could do with one of the most famous of Antipodean dishes, pavlova, which, the menu warns, is served "modern style", as though there were recognised fashions in international pavlova-ry. In practice, it's hardly a pavlova at all, spurning the characteristic sticky texture in favour of big soft billows of meringue, filled with a coffee-flavoured filling made with wattleseed. Mlle Pavlova would never have left the ground, had she tackled a portion of this size.

The good news, then, is that Osia delivers some memorable taste experiences, prepared with Japanese precision and Australian flair. The bad news is that it charges London prices. I've discovered what Osia really means; it's the involuntary noise that escapes when you see your bill; ours came to nearly £40 a head for food alone, with drinks and service bumping it up to around the £200 mark. The guide-book editors will have to get busy creating a new category for this seriously good newcomer. Just don't expect to see it listed under "Budget".

Osia, 11 Haymarket, London SW1 (020-7976 1313)