Brasserie Toulouse-Lautrec 140 Newington Butts, Kennington, London SE11

Ah Piaf, Lautrec, l'escargot... It's enough to give 'the armpit of London' a good name

It's hard to know what Henri de Toulouse-Lautrec would have made of Elephant & Castle. Even those of us who hail from south of the river don't challenge the view that the two roundabouts at its core are the armpit of London. So you'd think an artist as flamboyant as that master of fin de siècle Paris would struggle to find inspiration amid these dreary tower blocks. Perhaps it was their very greyness that prompted Hervé Regent to install a brasserie named after the painter here – next to The Lobster Pot, a 20-year-old fish restaurant he owns next door – and make it a family business by employing his eldest son front of house, and two others in the kitchen.

The locals should be glad they're here. The food is unexceptional and inconsistent, but the interior givesa lovely light, and the ambience comes easily. We walk into what feels, architecturally, like a country pub, except that the décor is all turn-of-the-20th-century France, and the mahogany roof-beams are suffused with the sound of Edith Piaf. It's an unnatural fit, but done with such gusto and unfailing Gallic generosity that somehow it comes off.

Upstairs, there is a jazz bar, with live music on Mondays bouncing off a white baby-grand piano. A hazy pink light beams on to the stage, creating the sort of scene to make one lament the smoking ban. Round the corner is a roof terrace for a "Gauloises break", with the canny touch of a blue plaque as French road sign. Downstairs, smartly dressed waiters complete the effect, and there is no shortage of tucked-away rabbit-warren tables for budding romantics.

Myself and three friends all try the £25 three-course menu. The rocket salad with warm chorizo and sun-blushed tomatoes and a balsamic dressing is very plain. The chorizo chunks are too small to reward mastication, and lack flavour; the rocket is, well, rocket. Tommy calls the dish "unremarkable". The home-made soup is a well-seasoned, creamy cauliflower, and the truffle oil is a good touch. My six snails from Burgundy come without shells in dimpled earthenware, but a wonderfully salty garlic butter makes it worth abandoning that New Year's resolve to build a beach body. Especially once I've had a glass of the Muscadet, reasonable value at £19.90 a bottle.

Tommy's Welsh shank of lamb really has been slow-cooked for 24 hours, judging by the ease with which it comes off the bone. The sweet redcurrant sauce in which it sits is an able companion, but the absurdly unadventurous sautéed vegetables on his plate are an affront to the French imagination.

Harry, to his credit, goes for the côte de boeuf (£10 supplement), which comes with a side-order of chips or vegetables and a choice of green peppercorn or – superb and very thick – Béarnaise sauce. He asks for it rare, and 15 minutes later one of the charming waiters arrives with a hunk of cow on a tray. They exchange furtive glances. The waiter wields his knife to expose puce flesh, checks this is OK, then cuts the beast into strips – which he ought not to have done, because despite being a man of refined taste, this is just too rare for Harry. And now, when the meat is taken away to spend another minute in the pan, it will return as stir-fried beef. Garçon: better to let my man cut his own meat, especially since when it returns, it is well worth the extra dosh.

I have the slow-cooked British pork belly, which is slightly overdone. But it is the focus of a really thoughtful plate – confit apple, pommes purée, a red wine and truffle sauce and, best of all, a boudin antillais. This is unbeatable black pudding: pork-blood sausages, heavily spiced. Compared with this, the two vegetarian options (tortellini and pan-friend tofu) sound dull.

Chocolate fondant is a good test of a chef, and it's hard to beat the soft and oozy number served with pistachio ice-cream here. The raspberry and passion-fruit sorbets are tangy and refreshing, and the crème brûlée is accurately done. They say, incidentally, that there's no service charge for parties of fewer than eight, but you'll want to reward these chaps properly. The same goes for Hervé and his sons. There's better French food around for this price, but as we reacquaint ourselves with the urban tyranny outside, their enclave of the Fifth Republic seems worth the premium.

6/10

Scores: 1-3 stay home and cook, 4 needs help, 5 does the job, 6 flashes of promise, 7 good, 8 special, can't wait to go back, 9-10 as good as it gets

Brasserie Toulouse-Lautrec 140 Newington Butts, Kennington, London SE11, tel: 020 7852 6800. Lunch and dinner daily. About £160 for dinner for four, including two bottles of wine and service

Brilliant brasseries

Les Deux Salon

40-42 William IV St, London WC2, tel: 020 7420 2050

This is the latest, and largest, venture from the highly regarded Arbutus/ Wild Honey team; a useful, if slightly pricey addition to Trafalgar Square

La Brasserie, The Chester Grosvenor Hotel

Eastgate, Chester, tel: 01244 324 024

It's expensive, but this smart brasserie of an unusually upmarket city-centre hotel offers a convincing pastiche of the classic Gallic experience

Café St-Honoré

34 North West Thistle Street Lane, Edinburgh, tel: 0131 226 2211

Hidden away in the middle of the New Town, this traditional brasserie is well worth seeking out; packed on any given day

Reviews extracted from 'Harden's London and UK Restaurant Guides 2010' www.hardens.com