Walking by an Ottolenghi shop front is no mean feat. The window opens on to a counter piled high with freshly-baked croissants, macaroons and its signature giant meringues.

Opposite is a culinary feast for those who want a little more from lunch than a rushed sandwich at their desk. The counter is covered with large bowls brimming with colourful salads and other delectable dishes. It looks fabulous, smells wonderful and tastes even better.

Though not exactly a household name, Ottolenghi is a favourite hangout for London foodies and celebrities like Julia Roberts and Claudia Schiffer. Two years ago it was voted the best place to go for breakfast in the British capital.

The restaurant-cum-delicatessen, which has four outlets dotted around London's coolest quarters, is the brainchild of Yotam Ottolenghi and Sami Tamimi.

Both were born in Jerusalem in 1968 - Tamimi on the Arab east side and Ottolenghi in the Jewish west. Separated by culture and religion, their paths never crossed.

But years later and thousands of miles away, a mutual passion for food drew them together.

In the late 1990s, each arrived separately in London. Sami had worked as head chef at Lilith's, in Tel Aviv, but had been head-hunted by a trendy Chelsea patisserie.

"I was there for four years and I left in 1997," Tamimi recalls. "I was doing well professionally, but it was the atmosphere that got to me. The stress was just too much."

Ottolenghi had a Master's degree in philosophy and literature and had worked as an editor at Ha'aretz. He thought about doing a PhD, but decided to take some time out in London first. Much to his parents' alarm, he enrolled himself in a cordon bleu course. Having qualified, he too was employed at the same patisserie.

The two hit it off and became firm friends. Eventually Yotam left to work on his own project - and invited Sami to come on board. That collaboration led to the creation of Ottolenghi, a small but dynamic chain of eateries. The Ottolenghi brand also encompasses a cooking school and a best-selling recipe book, now on sale in Israel.

"It was very weird, but felt natural," says Yotam about his partner. "In many ways we see things quite similarly. We have the same preferences in food. We like it to look and taste great, but not be too complicated. We like the simplicity of street food." But though geographically close during childhood, their cultural experiences were miles apart.

"Between Sami and me we have experience of quite a few cultures," Yotam says. "That reflects on the food. Sami grew up in a part of the Old City and I would experience Sami's food when I left my house. At home we had a much more European-style menu."

Much has been made about the successful partnership forged between an Arab and an Israeli. But though they welcome the positive media attention, they do not consider their friendship to be a recipe for peace in the Middle East.

"We don't like to emphasise that much," says Yotam. "We are just two people and don't see ourselves as representatives of anything apart from ourselves.

"We never talk about the whole Jewish/Arab thing because it doesn't exist in our relationship," Sami adds. "It isn't relevant to either of us. From the outside people see us and think it's amazing, but for us it's just about running a business."

So what makes Ottolenghi so successful?

The trendy white space is laid out almost like a communal dining room. Chefs can often be seen bringing up trays and plates, heavily piled with their creations. In a corner of the room are boxes upon boxes of fresh fruits and vegetables, piled high and delivered that day.

"It started off with us doing what we knew how to do," Yotam says. "We didn't really have a vision in mind. We had an idea that we were going to sell extremely fresh food. I noticed that there was a gap between the quality of food you got in restaurants and what you got at deli counters. We wanted to cook food with as much attention to detail and quality as restaurants."

The food is "real, it's alive, it's what you eat at home," says Yotam.

Ottolenghi welcomed its first customers to its Notting Hill branch in 2002. Two years later, the flagship store in Islington opened. Two additional take-out branches now exist in the affluent Kensington and Belgravia areas. England is not known for its culinary culture, but Ottolenghi has proved to be a massive success.

"London is so dynamic in terms of food," says Yotam. "This place is like a sponge. There are influences from all over the world."

Yet it's not quite the land of milk and honey. "I miss really good figs," Yotam says. "My parents used to have a great fig tree outside their house. And the apricots, too - the season lasts only for about three weeks here."

The workforce influences the international feel of the food. The staff, numbering over 100, includes five other Israelis, a branch head chef from Malaysia and a Swiss general manager.

"It's a very collaborative effort," says Yotam. "We talk about ideas and recipes. We always try to think about new ideas and combinations.

"Whoever comes to work with us has to fit in with this family and a lot of the time it doesn't happen," Sami adds. "They don't get rejected, but they do understand that this is how we work."

Though there are no plans to open more stores, the Ottolenghi brand is now available to foodies across Britain and beyond.

In 2006 Yotam started writing a weekly recipe column for The Guardian. It led to the publication of the hugely successful Ottolenghi cookbook.

Initiated through popular demand, it has since become a word-of-mouth best-seller. This collection of mouth-watering recipes includes the many aspects of Ottolenghi's repertoire - bread, salads, hot dishes, patisserie, cakes, cold meat and fish.

"People really enjoy cooking from this book. We take really great care with the quality of our recipes, cooking and checking them many times," says Yotam.

The book opens with an engaging introduction to the concept, the brand and its philosophy. The style is familiar, conversational, with their passion for food dominating throughout.

Sami is the company's executive head chef, while Yotam now concentrates on writing and developing recipes.

Ottolenghi is most famous for its giant meringues, which come in an interesting array of flavours including blackcurrant, raspberry, cinnamon and hazelnut.

But the "mighty aubergine," as they call it, is their best-selling ingredient. "We can't sell enough of it," Yotam says.

"It's quite rich and meaty, so it's an ideal meat substitute for vegetarians."

The Middle Eastern influence is unquestionable.

"For years I was trying to see and learn about different cuisines," Sami says, "but a few years ago I started going back to it. I always go back to my mother's cooking and childhood memories for inspiration."

Nevertheless the book had to be slightly adjusted for its Israeli readership.

"There was only one recipe that we took out," Yotam says, "and that was because it contained gooseberries and elder flower.

"No matter how hard you try, you will never find those in Israel."