Polpetto, Upstairs at The French House, 49 Dean Street, London W1

Grot factor: Polpetto has been decorated to resemble a down-at-heel New York hangout in the 1930s

Polpo, the no-reservations Italian tapas bar that opened in Soho a year ago, has been a big success. The dark, slightly dingy bar area always seems to be crammed with sneerily trendy chaps and amazingly pretty girls from the Regent Street shops and magazine HQs, even though the wine list is tiny and the food rather routine. It's so achingly on-trend that my eldest daughter asked to be taken there for her 23rd birthday.

Polpo's co-owners, Russell Norman and Richard Beatty, call the place "a Venetian bacaro in Soho". For those unfamiliar with La Serenissima, a bacaro is a friendly neighbourhood dive where the wine flows like a gondolier's song, the food is snacky but delicious, and the clientele are devotees of the dolce far niente. It's yet another retro dream in the heart of the glittery metropolis, but by golly it's working.

Norman and Beatty are now opening two new establishments, also in Soho. Spuntino is another bar-with-stools-around-it place, scheduled for this month but delayed. While we're waiting, here's Polpetto ("baby octopus") on the site of the old French House restaurant, one of the smallest dining rooms in London. How to describe the ambience? It's an exercise in carefully-wrought grottiness. The walls have been stripped back to brickwork, then painted in Farrow & Ball yellow so that the brick shows through like bruises. They've picked up some reclaimed church windows and set mirror tiles where the glass used to be. Salvaged ancient French light fittings poke out at angles. Handmade zinc tables have been "distressed" and tarnished to a vindictive degree. The ceiling of wooden squares comes from a Connecticut warehouse. You realise that this small, scruffy room has been got up to resemble a down-at-heel New York hangout in the 1930s. The lunchers at the eight or nine tables (there are just 28 covers in all) seem unfazed by the grot factor. They include the American flaneuse and sex therapist Karen Krizanovich, Helen Brocklebank from Esquire who writes the Mrs Trefusis blog, and other glamorous media types, looking as if they've been coming here for years.

The menu arrives on recycled ochre paper, its contents as stripped-back as the furnishings. Some dishes get one word (Polpetti, Panzanella), some a loquacious two (Piazzeta Bianca, Zucchini Fries), some even more. Instead of starters, there are Cicheti (tiny bites, like canapés) and "Breads", but the breads cost as much as the meat and fish courses. Were they all tapas? "We're not supposed to say the T-word," said our charming waiter, Olly, "but that's the general idea." So my friend Madeleine and I ordered four teeny starters and two main courses each. (And a half-litre carafe of white wine, to be drunk from tiny Lilliputian glasses.)

The Cicheti were mostly delicious: polpetti themselves, knobbly, wiggly, drenched in oil and garlic, were far tastier than their grown-up equivalents; a sliver of smoked swordfish, filled with dill ricotta and touched with lemon juice, was a tiny tri-flavoural dream; a crostino of chicken liver was smooth as an angel's cheek but involved too much bready chewing; only the duck and porcini meatball failed to impress – it seemed generic in its tomato sauce, with no trace of duck about it.

Timings at Polpetto are a little brutal, as they are at Polpo. If you've ordered a dish, it'll arrive when it's ready. So the main courses came before we finished the starters – and we looked with dismay at their size. Madeleine's Sarde in Soar, or pickled sardines in onions, pine nuts and sultanas, were fine in their agrodolce, bitter-sweet, way – but were a meal in themselves. My crispy soft-shell crab, in its Parmesan batter, was the size of a policeman; it lay across the plate with both its boots and its helmet (so to speak) sticking off the edge. A wonderful complex of tastes, from the crispy, cheesy batter to the sliced-fennel coleslaw, it was a fulsome tribute to the crab genus. But as I raved about its excellence, I watched the other main courses arriving, Madeleine declared herself full up and I knew I was sunk. The pigeon saltimbocca was a lovely variant on the classic veal dish (literally "jump into the mouth"), the flavour of game far from overwhelmed by the Parma ham wrap. But I couldn't do justice to the osso buco. Tender, unctuous and melting, it was served on a lovely saffron risotto which would have satisfied a platoon of trenchermen.

As I tried to find an abdominal corner for the scrumptious pannacotta with blackberries and biscotti, and basked in Polpetto's lovely informality at 3pm, I wondered if I'd ever complained before about a restaurant serving too much food – especially when most dishes were so well achieved. The Polpetto management has to clarify things for their clients. Are they a tapas bar, devoted to "small plate" snacks? Or a purveyor of full-sized home cooking at eccentric prices, in which the soft-shell crab is £8, and the roast potatoes £4.50? I'd recommend the place to any Soho voyager – provided they find out exactly what they're getting.

Polpetto, Upstairs at The French House, 49 Dean Street, London W1 (020-7734 1969)

Food
Ambience
Service

About £70 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"

Side Orders: Little Italy

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