Between the overflowing rails and ringing tills of London's Selfridges is a real reason to go shopping - Mourad Mazouz's best Moroccan restaurant yet

On paper, it shouldn't work. In practice, it shouldn't work. A Moroccan café on the second floor of London's Selfridges department store, surrounded by the world's most expensive designer gear, for heaven's sake? No way.

The new dining establishment of Momo's Mourad Mazouz turns the Selfridges Superbrands department into a sort of far-fetched, surreal, bizarre bazaar. But then, to Mazouz, far-fetched, surreal and bizarre are not so much negatives as an on-going business plan.

So far, he's given us a Moroccan restaurant that depends as much on the skills of its dancing waiters as those of its kitchen (Momo); a café that can't decide whether it's a quixotic lifestyle store or a tea room (Mo); a brasserie that has to wait for itself to stop being an art gallery by day before it can start being a brasserie by night (Sketch Gallery); and a restaurant that managed not just to break through the price pain barrier, but to smash it to smithereens (Sketch Lecture Room and Library).

In the light of all that, the idea of a glamorous cocktail bar, laid-back restaurant, tea room and hookah-smoking den ensconced in a glass "tent" in the middle of a shop probably sounded quite sensible.

There are several food outlets in Selfridges, but none rocks the boat like this lush, glowing oasis in the middle of a designer desert (ahead of Momo is Alexander McQueen, to the right Chloè and Burberry, to the left, Dolce & Gabbana, behind is Marni).

Modern department store design is all about staging and manipulating excitement, ratcheting up our energy levels with bright lights, music and visual theatre until we hyperventilate into buying something. But once inside this oasis, reclining on a cross-stitched hide chair at a little table of rose marble, attended by easy-going if un-dancing waiters, an unwinding begins and the forced razzmatazz and cacophony of the medina melt away.

It is nothing like, and yet everything like, Café M'Ramet, a magical bar/café in the middle of the madness of Tunis's medina, where buyers and sellers flock to smoke, drink pine-nut tea and listen to local music. Here, the music is as addictively mesmerising and rhythmic, from Mazouz's Arabesque compilations, and the tea is as fragrant, but smokers are corralled into a little cushioned den, and there are cocktails to buy instead of carpets.

All around, women park Selfridges bags and prams, while men shed camel-hair overcoats to sit down to platters of couscous. A Pure Oasis cocktail of gin, lychee purée, rosewater and champagne adds to the general winding-down process.

The menu is light and snacky in the café, but the restaurant runs a serious mix of Moroccan classics (pastilla of pigeon, lamb-shank tagine) and adventurous yet intelligent attempts at a Middle-East-meets-West fusion (roast monkfish tail with merguez and white-bean cassoulet, crab and preserved lemon tart).

Head chef David Jones, last seen at Chintamani, does a Frenchified vegetable couscous (£8) that is the perfect lunch dish. The semolina so light and fluffy that, when I gently blow on it, the table is covered with golden grains like the Sahara itself. Arranged around the couscous are some well-turned vegetables and tomato concasse, and it comes with bowls of hot broth and chilli-hot harissa. I can't imagine that anything from the menswear department would suit me better.

A vegetable tagine (£12.50) is served in its traditional chimney-pot terracotta dish, as a steaming winter landscape of baby veg underpinned by sweet oniony juices, honeyed fig and preserved kumquat. Similar sweet-spicy-aromatic-woodsy tones come in a tagine of fall-apart duck confit (£12.50) teamed with pearl onions, more honeyed figs and clementine marmalade. It is duck à l'orange à la Casablanca.

If you just want to nibble, the Kemia (£8.50) meze platter is the best idea. You get well-flavoured mechouia (Moroccan ratatouille), zaalouk (creamy aubergine dip), bourek (chicken and spices in brik pastry) and briouat (a filo triangle filled with chermoula flavoured cod), with a glass of Moroccan rosé thrown in for an extra £3. Only the briouat fails to thrill, tasting fishy and strangely seasoned.

Overall, the cooking is another level up from the Momo mothership in Mayfair. It is mannered without being too contrived, and has life, punch and freshness.

For dessert, Moroccan pastries (£4.50) do what Moroccan pastries do, with their usual honey, sesame seed and sweetness overload, but a super-creamy ras el hanout ice-cream (£4) is a revelation. With its warm mix of cayenne, turmeric, cinnamon, cardamom, cloves and rosebuds, it's the first curried ice-cream I have ever eaten, and weirdly, it works.

But then, everything about this place works far better than I - or even Mazouz - could have imagined. Momo at Selfridges has achieved the impossible by making me look forward to going shopping in Oxford Street. I'm now planning forays for furniture and fashion on Sundays, cleverly designed around a long, lazy lunch. I may have to compare flat-screen televisions after Berber pancakes for breakfast mid-week, and pick out a new tie around the cocktail hour. And I can't wait for the next big storewide sale.

15 Momo at Selfridges Superbrands 2nd Floor, Selfridges, 400 Oxford Street, London W1, tel: 020 7318 3620 (no reservations). Open daily. Around £60 for two, with service and wine

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

Second helpings: Other North African restaurants

Moroccan Tagine, 95 Golborne Road, London W10, tel: 020 8968 8055
What a sweetie: a cheap, cool and casual no-frills caff, Tagine does a roaring trade in several variations of its namesake dish including the house special kofta tagine. No booze, but a gleaming pot of mint tea is perfect after a well-seasoned harira soup, a spicy carrot salad and the mighty couscous royale, served with lamb chicken and merguez sausage.

Al Fassia, 27 St Leonards Road, Windsor, Berkshire, tel: 01753 855 370
Windsor might not be the last word in gastronomic exotica, but Al Fassia is deservedly popular for its minced beef briouts, chicken and prune tagines and beef kofta brochettes. Mine host Mustapha thoughtfully supplies orange-blossom water for freshening the fingers after eating with your hands (thumb, index and second fingers, right hand only please).

Adam's Café, 77 Askew Road, London W12, tel: 020 8743 0572
By day it's just another greasy spoon, but by night, this Shepherd's Bush favourite transforms into a lively, friendly, family-run Tunisian café complete with tablecloths, candlelight and Arabic music. The cooking is a mix of Tunisian and Moroccan, from fish soup, briks and merguez to the ever popular couscous royale. Portions are big, bills are small.