Occo, London W1

Occo may see itself as Marylebone's answer to sophisticated modern Moroccan eateries such as Moro and Momo, but it's more chain bar than Kasbah

Even now, gently twisting the cap from a bottle of Schweppes fills me with sheer Schweppervescence. During my early years as an advertising copywriter, the campaigns for Schweppes were iconic. One of the best was Ogilvy & Mather's Secret of Schhh campaign, with its sibilant "Schhh" as the gas escaped. When the account moved on, the magic didn't. The new agency then astounded everyone with a campaign centred on a secret ingredient called, unbelievably, "Weppes". Needless to say, it fell flat - as the trade magazine Campaign commented following the launch: "Jesus Wepped".

Even now, gently twisting the cap from a bottle of Schweppes fills me with sheer Schweppervescence. During my early years as an advertising copywriter, the campaigns for Schweppes were iconic. One of the best was Ogilvy & Mather's Secret of Schhh campaign, with its sibilant "Schhh" as the gas escaped. When the account moved on, the magic didn't. The new agency then astounded everyone with a campaign centred on a secret ingredient called, unbelievably, "Weppes". Needless to say, it fell flat - as the trade magazine Campaign commented following the launch: "Jesus Wepped".

And now here I am at a restaurant called Occo. It's Moroccan, you see - with names such as Moro and Momo already being taken, the owners decided to do a Weppes and claim the arse-end. Couldn't they just have called it Losersville and be done with it? Despite some nice touches - the bar is inlaid shell, candles flicker in bejewelled holders, and the banquettes and bar walls are lined with the rough-hewn fabric of the traditional djellaba (hooded robe) - the place seems like an All Bar One with added couscous. It's full of chain smokers and chain drinkers, without actually being part of a chain.

There's a hide-away chill-out den, and a semi-private dining room in an odd interior courtyard arrangement that appears designed for large parties. Tonight it is taken over by a group of 16, so we eat in the large front bar at a table next to the emergency exit and a fire extinguisher. My wife slides continuously off the banquette, but she says it isn't her fault as the seat slopes forward. I wedge a leg against her knees, and she stays put.

Any dreams I had of exotic casbah cooking and sensuous, fragrant tagines disappear in a puff of my neighbours' cigarette smoke. Around us, a mixed after-work crowd drinks pints of lager and eats battered calamari, pink slices of duck breast, potato wedges and cheese platters. It all looks about as Moroccan as borscht. Still, I find a few things on the menu that give more than a vague nod to the Maghreb, such as the briouat (£5.75), a traditional pastry, in this instance filled with minced chicken, almonds and cinnamon. It is heavy, solid and sweet, rather than flaky and fresh, and the dressing on the accompanying green salad is also cloyingly, annoyingly sweet.

Occo's shorba (£4.95), or chorba, is a soup made of slow-roasted vine tomatoes, chickpeas, puy lentils and coriander. While highly flavoured, it is dense without depth; a soup waiting for something. Traditionally, it would have been built on chicken or lamb or both, which would have given it more presence.

Most of the world's wine-producing countries, including Morocco, are represented on what feels like a very personal wine list, and a Luce Monaca Monferrato (£23) is a succulent blend of barbera, cabernet and merlot. It's too warm, but a good waitress shocks it in ice without any fuss. It's also a little too assertive for a well-cooked saffron-marinated chicken breast (£12.75), which, in spite of the saffron and a "tagine" (more of a dressing, in this case) of coriander, olives and preserved lemons, is quite mild-mannered. A bed of roasted potatoes makes the chicken feel more Midwest than Middle East, and a mixed-leaf salad (£3) is as sickly sweet as the previous one. I wish the chef would take his salad-dressing recipe - which I believe involves argan oil and maple syrup - and bury it.

There is not a great deal to be gained from a dish of red mullet marinated with fennel, cloves, peppercorns and cinnamon (£14.50). The two fillets are firm surfboards of overcooked flesh, and the whole thing feels dry. An accompanying mound of almond and prune couscous, while not steamy and fluffy, is still couscous, which means it is still good. Just being couscous seems to transcend all manner of sins, like just being Stephen Fry, or just being Kate Moss.

To finish, a platter of Moroccan pastries (£5.50) is endearing in its child-like simplicity. Another dish piled high with small, puffy, warm, rosewater-scented doughnuts (£4.95) is cute in a mini-Krispy Kreme sort of way, but you have to wonder just how much sugar you can take in a single night.

It seems that Occo sees itself as Marylebone's answer to Momo, with its beat-driven Moroccan remix music, rose petals strewn on stairs, and soon-to-open downstairs members' bar. But the two are chalk and cheese platter: one being seductive, sophisticated and original, the other commercial and derivative. The food seems deliberately dumbed-down to appeal to a wider audience, and I am not convinced of the quality of some of the raw produce or by the skills of the kitchen. But why do the owners feel they have to do modern, anonymous bar food, when we are crying out for great Moroccan dishes in a fun, relaxed setting? We need fragrant, slow-cooked tagines steaming under their conical lids, fiery harissa, and m'choui of spiced, spit-roasted lamb more than we need "sesame and herb-crusted goat cheese and rocket salad with roasted walnuts with maple syrup and argan oil dressing". In other words, we need Moro and Momo more than we need Occo.

10 Occo 58 Crawford Street, London W1, tel: 020 7724 4991. Lunch and dinner are served daily. Around £80 for dinner for two including wine and service

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 tastes of north Africa

Al Fassia 27 St Leonard's Road, Windsor, tel: 01753 855 370 Outside London, Moroccan restaurants are thin on the ground, so the residents of Windsor are better served than most with this extremely popular family-run restaurant (bookings are a must). It looks like the real deal with its wall hangings and tiled tables, and the food runs to all the usual Moroccan faves, from tagines and couscous to skewers.

Sami's 49 Harrogate Road, Chapel Allerton, Leeds, tel: 0113 262 1676 Cheap, cheerful, and buzzy, Sami's does the whole themed thing with hookah pipes and cushions. Favoured dishes include chicken tagine with preserved orange and saffron rice, and couscous with marinated, spiced lamb, but the food is more than Moroccan, running around North Africa and the Middle East with Syrian fattoush salads and Tunisian pastry briks.

Momo 25-27 Heddon Street, London W1, tel: 020 7434 4040 Momo is a nonstop come-into-my-Casbah party, with its rustic artefacts, wooden screens, bordello lighting, laid-back lounges and pulsating, rhythmic music from owner Mourad Mazouz's "Arabesque" compilations. The staff dance around the tables, everyone is in a good mood and, if you stick with couscous and, say, a tagine of chicken and preserved lemons, the food is as much fun as the scene.

E-mail Terry Durack about where you've eaten lately at t.durack@independent.co.uk