Trishna is a clever name for an Anglo-Indian restaurant, since it skilfully conflates Krishna, the Hindu deity, and Trisha, the state-of-England, daytime-TV, chavs-in-a-pickle show. But when you first clap eyes on its graceful double-frontage, it's so far from the Indian stereotype, you wonder if you've come to the right place. The décor is minimal, like a chic Chelsea schoolroom: whitewashed walls, pale grey-green wooden slats like the backdrop of a Hammershoi painting, wood and marble flooring, chrome lamps, gleaming glassware. It's marvellously fresh and clean looking. Of flock wallpaper, pictures of Bollywood queen Aishwarya Rai and the whiff of fenugreek, there was no sight (or trace) at all.

On the day we lunched there, the waiter was young, European-looking and strangely nervous, even as he described all the special dishes with impressive fluency. It took a while to work out why. When I finally asked where he came from, he gazed at his shoes and muttered "Austria", as though crippled with proxy guilt about Josef Fritzl. Really. It was hard to find a trace of India anywhere.

There were, however, Indian ladies, out in force. A dozen high-maintenance Indian WAGs in pastel-coloured salwar-kameezes and shimmery cotton blouses, sat around a table chatting, uttering theatrical cries of delight or dismay. It's a compliment to the place that they seemed determined to colonise it as an emblem of their success. You can see why they would. Trishna has a fair claim to call itself the coolest Indian restaurant in London.

There's a famous Trishna seafood restaurant in Mumbai, which regularly inspires delirious flights of rapture from well-travelled foodies. The chef in the London Trishna isn't from there – he's Ravi Deulkar and he's been head chef at the Michelin one-star Rasoi Vineet Bhatia for seven years. Apparently, he spent a year before Trishna opened, wandering through India's south-west region, picking up tips from relations (such as grinding your own spices every day).

You know you're in safe hands from the moment a brace of poppadoms is reverentially laid before you with two sauces. This ritual has begun every Indian meal I've ever known, but the Trishna version is different. Everything is made on the premises, the green sauce is a fresh coriander-mint soup, while the red one's a shrimp and tomato chutney, chewy and delicious. And everything is served on interesting long white platters or special copper saucepans with long, drooping handles. It's approximately 100 light years away from The Star of India curry-house of my childhood.

When this Trishna opened last autumn, the prices were ruinous (lamb cutlets £21, fish tikka £24) and have now been shrewdly re-thought. A fixed-price lunch of £25 lets you choose three courses from the à la carte, with a carafe of wine thrown in, and rice and breads gratis. We chose one starter from the "pakora" section – deep-fried squid, with sliced raw chilli and lime sauce, very toothsome and spiced, but in need of a dipping sauce – and from the "char-grilled" section I ordered twin fillets of bream. They'd been marinaded in ginger and garlic, and came covered in a green sludge of coriander mint, with a rudimentary salsa of cherry tomatoes called a "katchumber", which is supposed to be char-grilled but wasn't. The bream was perfectly cooked, firm on the fork, melting on the tongue, and retained its dignity even as its slimy green exterior minded you of Lord Mandelson.

Mains, sluiced down with a nice (free) decanter of Côtes du Rhone, were terrific. The Isle of Shuna Mussels, sourced in Scotland, had been marinated in coconut milk and turmeric until they were softened and swollen and succulent, then served with a dash of ginger, shallots and lime juice. Absolute bliss. My "coastal" lamb curry looked ordinary but packed a wallop of black pepper, roasted coconut and poppy seeds. It was hot and rich and guaranteed an afternoon of drowsing at one's work station. The basmati rice was fluffily perfect, and the successive waves of bread just right – it's a good sign when care is taken with the free accessories.

My only problem was the pudding. I've read about their famous mango rice pudding, with chilli and pistachio, and decided to chance it, despite my lifelong hatred of rice pudding. It looked like uncooked scrambled egg, with a snail-trail of chilli oil, and it tasted like Ambrosia Creamed Rice with slithery lumps – too runny and sweet to entertain the palate.

No matter. Trishna is a real find. It may be about as authentically Mumbai as Slumdog Barbie, but it's genuinely good. Everything is carefully cooked, subtly seasoned and beautifully presented, and its current pricing strategy is excellent value for money. No wonder the well-groomed Delhi dolls around the big table look so pleased to have discovered it.

Trishna, 15-17 Blandford Street, London W1 (020-7935 5624)

Food 4 stars
Ambience 3 stars
Service 3 stars

About £60 for two, with wine

Tipping policy: "Service charge is 12.5 per cent discretionary, of which 100 per cent goes to the staff; all tips go to the staff"