It's the meringues that stop the traffic.

It's the meringues that stop the traffic. Cartoonishly huge horns, dusted with cocoa, they form the centrespread of a window display of total, shameless gastroporn. Bulbous chilli peppers, purple-tipped artichokes, pert croissants, glossy fruit tarts; this is the foodie equivalent of an Ann Summers shop; you either bustle past with eyes averted, or stand there, tongue hanging out, brazenly lusting.

The windows belong to Ottolenghi, a state-of-the-art deli and diner which has just arrived on Islington's increasingly smart main thoroughfare. It represents London's most convincing attempt so far to replicate a style of eating that is done so well in Sydney or LA. An all-day, muesli-to-Muscat kind of place where you can drop in to enjoy seriously good food in an informal, almost casual manner on the premises, or fill your bags with those exquisite home-cooked goodies you never quite have time to cook at home.

The deli counters groan under a display of glorious abundance. A giant skillet of golden cornbread gleams under scattered curls of red chilli pepper. Fabulously colourful salads and vegetable dishes are heaped in Provençal bowls - globe artichokes brimming with tiny peas, baby carrots bathed in orange zest vinaigrette, golden slices of roasted butternut squash dressed with tahini. Cuts of meat and fish gleam provocatively over bundles of fresh herbs. Unusual breads (baking legend Dan Lepard's been at work here)are piled high next to trays of light-as-air pastries.

There's no need to make a reservation if you're eating lunch in. You're shown to one of the shared refectory tables and handed that day's menu, which lists all the creations you've just been slavering over. Each table sports its own gleaming Kitchen Aid toaster, an oddly homely touch in a decorative scheme as shinily all-white and perfectly lit as a photographer's studio. "It's like a nightclub with toast!"one of my guests squealed in delight. Happily, the cool décor doesn't reflect the summery exuberance of the food, which is broadly Mediterranean, with Arabic, Greek and Maghrebi borrowings.

The menu structure is flexible; you can put together your own selection of three or four salads (for £7 and £9) or add one of that day's main courses for an extra couple of pounds. Here are some of the things we tried and loved: roast free-range chicken legs dressed with pomegranate juice, garlic and pine nuts; a broccoli and Serrano ham quiche with the shortest, crispest pastry imaginable; sweetly roasted lamb ribs with onion and thyme; cold slices of roasted beef fillet seasoned with mustard and black pepper. Some of the veg could have done with slightly longer cooking - I'm not a fan of crunchy broccoli or asparagus - but all the salads were executed with an interesting twist, nigella seeds tempering the sweetness of roasted butternut squash, and chilli and sesame seeds adding Oriental complexity to a tangle of asparagus and samphire. We only struck out once, with an over-sweet pairing of green apple and sweet potato, dressed with granola and thyme. Shouldn't we have guessed?

The chorus of approval from the squadron of Yummy Mummies I'd assembled to give the menu a thorough work-out was led by my friend Sharon, who claims to have been to Ottolenghi every day since it opened, and hasn't stopped raving about the food. She's no pushover, either: she has just returned from living in deli-tastic Venice, CA, and is so high-maintenance, even her baby is lactose-intolerant. She was crestfallen when she learnt that her new favourite restaurant was the sister to an existing Ottolenghi in Notting Hill. "You mean it's a chain?"

In fact, the owners, chef Yotan Ottolenghi and his business partner, aren't looking to roll this venture out. There's no centralisation between the Islington and Notting Hill branches - both cook everything they serve from scratch, and each has its own head chef. In Islington, they've recruited Esther Mordo from Yoezer Wine Bar in Jaffa, one of Israel's best restaurants.

With its day-long opening and flexible menu, Ottolenghi has already become a canteen for all manner of trendy Islingtonites; business lunchers, singles on the pull (you can imagine those toasters coming in very handy: "Excuse me, would you mind just popping my sourdough?") and performers and audiences from the nearby Almeida Theatre. I was sure I spotted several semi-recognisable actors in the place, and that was just the waiters. Ours took it on the chin, so to speak, when his piercing was greeted by one of the younger members of our party with a horrified shout of "He's got something on his face!"

Thanks to a chocolate brownie of melt-in-the-mouth lightness, we left our little corner of Ottolenghi rather less pristinely white than it had been. We also tried one of those indecent meringues, which come filled with strawberries and cream. Expecting a kind of self-contained Eton mess, the recipient was disappointed to find they'd used strawberry jam rather than fresh strawberries, with rather synthetic-tasting results. "That's the thing about meringues," she said wistfully. "They look so much better than they taste." Which would have been a perfect metaphor for this shiny, white confection of a restaurant, if only the food hadn't tasted quite so good.

Ottolenghi, 287 Upper Street, London N1, 020-7288 1454

SECOND HELPINGS: DELI BELLIES

By Caroline Stacey

Café Paxton

Paxton & Whitfield's beautiful new Birmingham branch has a temperature- controlled cheese- maturing room, and a café so cool it serves fondue. Cheesecake for pudding, of course.

27-29 Wharfside Street, Birmingham (0121 632 1440)

Daylesford Organic Farm Shop

The barn's interior- designed, the café's partly alfresco in a yard that's more courtyard than farm, without an animal to be seen. Countrified celebs flock here for exquisite organic food.

Moreton-in-Marsh, Glocs (01608 731700)

La Fromagerie

If the cheeses, charcuterie, tarts and cakes in this reverential temple of wonderful food make you want to eat whatever you see, you can. Join the communion at the refectory table.

2-4 Moxon Street, London W1 (020-7935 0341)

The Olive Tree

More than a dozen different olives glisten invitingly in the deli and from saucers in the upstairs café. Cheeses, and fancy groceries downstairs; Mediterranean-style lunches above.

353 Ormeau Road, Belfast (028 9064 8898)