According to Ottolenghi, the most common factor between the Jews, Arabs and Christians is their mutual proximity to "the terroir" - the soil - of the city. "Jerusalem is quite small but its spread out over quite a large area," he explains. "It's located in the Judean Hills, so the countryside is very apparent. Wherever you go, you see areas that are not built up, unlike in London. If you grew up in the city - which Sami and I did 30 years ago when it was even less built up - you would see shepherds with their goats and sheep and people growing their own food. That influences the food very much, the fact that on your way to work or school you can walk through a field where there are wild herbs growing. That's really the smell of the city and I've tried to capture it in the book."
Despite their bitter religious divisions, Ottolenghi believes that the cooking styles of Jerusalem's numerous cultures share many of the same elements and textures. "You can go to somebody's house and they will say 'this is my dish, I cook it in a certain way' but in actual fact, there are other recipes that are very similar but are just called a slightly different name," he says. "There's a lot going on, which is why researching the book was so interesting. We'd start off with one dish, which would very quickly lead you on to another dish by somebody else."
The close connection between the various culinary styles is best illustrated by a basic dish of couscous with tomato and onion, which was a staple of both his and Tamimi's parents. However, because Ottolenghi's father Michael was Italian, he made it with small pasta balls called ptitim. "For every stone we turned over, we'd find something else exciting, whether it be through colonisation or immigration," says Ottolenghi. "Jerusalem is such a dynamic place. People have been immigrating to it for centuries and they all have different influences. You could go back 4000 years but you don't have to go back so far. Most of the Jews in the city have arrived over the last 100 years. Israel is a very young place in many aspects but it's also got a local indigenous community of Palestians that have been there for many hundreds of years. They have great food and a very rich tradition of cooking. When all of those aspects interact, you get some seriously delicious food."
While the often bloody, political battles between the different factions have driven the Jews and Arabs even further apart, Ottolenghi maintains food still has the power to bring folk together. "I'm not too optimistic about what's been happening in Jerusalem over the past 15 years so to say that it can be a unifying force would be like painting a too rosy picture," he says. "It's a difficult situation in general but if anything can be a unifying force, it's that. People tend not to mix - and I would like to see people mixing more - but it can sometimes happen around a restaurant or kitchen table, which makes you a bit more optimistic for the times."
Ottolenghi admits he is still surprised by the massive success of Plenty, which has become a fixture in kitchens as far afield as New Zealand since it was published in 2010. "I was having dinner with Peter Gordon in a restaurant in Wanaka a couple of years ago and Peter said, 'I bet they've got your book'," he recalls. "I said, 'What do you mean? We're in a tiny place on the other side of the world. I'm sure they don't.' He said, 'No, I can see that they do by the cooking.' He then went to talk to the chef and suddenly there was a copy of my book. I was completely stunned."
Some readers of Plenty, solely composed of tantalising vegetable dishes, were confused to discover that Ottolenghi - who wrote the book on his own - is not vegetarian himself. But after including carnivorous options in their 2008 debut Ottolenghi: The Cookbook, he and Tamimi explore the likes of mixed grills, roast chicken and cod cakes in Jerusalem. "I didn't want to make Plenty into a classic vegetarian cookbook," he says. "It was just a book with fantastic recipes that just happen not to have meat and fish in them. The vegetarian label can be quite restrictive and it can exclude a lot of people, even those who want to cook more vegetables. My approach was always very different; that you don't have to put a label on it. You can eat meat and fish but still be very keen on vegetables and on trying to eat less meat and fish."
A fan of London's expat New Zealand-owned establishments like Providores, Kopapa and the Modern Pantry, Ottolenghi feels a certain kinship with his antipodean cousins. "There's a certain lightheartedness and a happiness to explore things about both my style and the Kiwi style here in London," he says. "The idea that nothing is too sacred. You can play around with food as opposed to very traditional French or Italian cuisines, which I think is to do with New Zealand being quite a young nation. There isn't a heavy tradition where you feel that need to follow in the steps of this or that person, who was there about 300 years ago. In that respect, we think quite similarly. It's all about the flavours, the colours and the beauty and less about what it says in any book."
* Jerusalem by Yotam Ottolenghi and Sami Tamimi (Random House $64.99).