Momo, 25 Heddon Street, London W1

Restaurants come and restaurants go, but every now and then, they stay. Le Caprice, 25 years. The Waterside Inn, 35 years. Mr Chow, 39 years. Le Gavroche, 40 years. Rules, 209 years.

Set against such longevity, a mere 10 years is no more than a drop in the champagne bucket. But Momo isn't just still here, it's still an overnight success, every single night. So great is the charm of this North African shrine to music, couscous and mint tea, that when owner Mourad (Momo) Mazouz recently threw a 10th birthday party for his closest friends and most regular regulars, over a thousand people turned up to rock the casbah. It would have been more, but it was raining.

Mazouz has a lot of friends in the music, fashion, art and media worlds, who move like shifting sands through the ground-floor restaurant, the downstairs Kemia bar and the next-door Mo Tearoom & Bazaar.

I adored it in the early days, when sinuously hipped waiters would dance between tables and scented rosewater would be poured over your hands. The food - Moroccan with a Parisian accent - was never the real point of the place, which was to transport you on a magic carpet to a more exotic world.

Ten years later, the joint is still jumping. With all its intricate detail - stone walls, hand-blown glass lamps, filigreed wooden window screens, low-slung tables and cushion-strewn banquettes - it's The Wolseley of the Maghreb. I'm hyperventilating already at the mesmerising music, and the steamy, sweet smell of couscous, cumin, cinnamon, saffron and ginger in the air.

In 1997, a menu full of things like mechoui, briouats and tagines may have been brave, but these days, the food can no longer rest on novelty, but must have an authenticity, comfort factor and creativity of its own.

After a basket of freshly baked olive bread, I start on a deep glazed bowl of harira (£6.50), the earthy, homely Moroccan lamb and vegetable soup traditionally used to break the fast during Ramadan. Spiked with coriander oil and strewn with chickpeas, its dense, forceful character fills the mouth with spice and flavour. In contrast, a pastilla (£10) parcel of moist, minced pigeon, sugar and spice wrapped in filo is a festive, head-spinning mix of sweet and savoury.

The list mixes Algerian and Moroccan wines with big-hitters such as a 1995 Latour at £425, but a lighter Beaujolais style, like a Pinot Noir-ish Domaine Cret des Garanches Brouilly, at a steepish £29, is more spice-friendly.

The best dish at Momo is Couscous Momo (£17.50) - it's not just one dish, but a colourful, action-packed four-ring circus. First is a hefty platter of skewered lamb, a skinny, spicy Merguez sausage, and an entire lamb shank, its meat softly clinging to the bone. Next comes a conical pile of golden semolina, followed by a bowl of consommé-like broth loaded with subtly spiced turnips, courgettes and carrots, and a tray of condiments - harissa chilli paste, rose-watered sultanas and tender chick peas. The tiny grains of couscous, steamed the requisite three or four times, are like particles of the lightest, dreamiest, airiest desert sand.

A main course of cod tagine (£19) is less dazzling, featuring a slab of beautifully cooked, under-seasoned fresh fish on a slightly dull bed of potatoes, tomatoes and onions and some cute salt-cod fritters. To finish, a platter of various Maghrebine sweet pastries are fine.

Ten years on, Momo is a great London restaurant. Staff members have energy and enthusiasm; the kitchen under Mohamed Ourad has its groove back; and there is a strong core of professionalism beneath the hippie-go-lucky charm. It's busy, loud and crowded, and can be militant when it comes to turning over tables, but like all good restaurants, it has the power to transform. In you go, cold, hard and controlled; and out you come, soft, warm, and dancing. I think we can handle another 10 years of that. s

15/20

SCORES 1-9 STAY HOME AND COOK 10-11 NEEDS HELP 12 OK 13 PLEASANT ENOUGH 14 GOOD 15 VERY GOOD 16 CAPABLE OF GREATNESS 17 SPECIAL, CAN'T WAIT TO GO BACK 18 HIGHLY HONOURABLE 19 UNIQUE AND MEMORABLE 20 AS GOOD AS IT GETS

Momo, 25 Heddon Street, London W1,tel: 020 7434 4040

Lunch Monday to Saturday, dinner daily. Around £100 for two, including drinks and service

Second Helpings: More Moroccans

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There is something celebratory about this brightly decorated restaurant, with a menu that runs from snail soup to stuffed peaches with saffron and honey.

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In Omar Maftahi's Cathedral City restaurant, in addition to the tajines, couscous and kebabs, there are regular performances by a Middle Eastern dancer.

Pasha

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Try a cocktail in the Kemia lounge before descending to the sumptuously decorated restaurant below, where you can tuck into slow-cooked lamb shoulder.