Israeli food writer Gil Hovav was on hot form. His first session at Sunday's Gefiltefest, the foodie equivalent of Limmud, was on how to make zchug, the fiery Yemeni salsa.

Generous bunches of coriander lay on the table along with heads of garlic, bags of green chilli and assorted spices, alongside hand-held blenders. Such electronic gadgets were unavailable to his grandmother in Israel who taught him the recipe when he was young. "Every Yemenite kept a big black volcanic rock under the stove and with that you would grind your herbs," he explained.

As the blenders got to work, the vapour of herbs began to fill the air. "It has no oil, it is very healthy," he said. "It is shiny green, but later it gets dark green because it oxidises. But even when it is dark, it's still very good."

Zchug was an unknown quantity to Joseph Alfon, 13. "But my dad will probably like it because he likes spicy things," he said.

Michael Joseph, of Joseph's Bookstore in Golders Green, was also game. "I have no idea what it tastes like," he said, pounding his chillis. "I will soon find out."

When Gefiltefest launched four years ago, it attracted 200 people. Organisers put this year's attendance at more than 700. In the grounds surrounding the London Jewish Cultural Centre, stalls sold cupcakes, burgers, organic eggs and Hendon-made hummus. Inside, there were over 60 cookery demonstrations, talks and classes featuring leading cooking writers such as Elisabeth Luard, Claudia Roden, who has written the foreword to the new Gefiltefest Cookbook, and American Joan Nathan, author of Quiches, Kugels and Couscous.

You could learn how to pickle herring or de-bug lettuce, or take a gastronomic tour of the Jewish world with dishes from Libya, Tunisia and Syria.

When Linda Dangoor, author of Flavours of Babylon, helped to make mahallabi, an almond milk pudding, as a child in her native Iraq, they would grate the almonds one by one with a cheese-grater. "Now you can put them in a magimix," she explained.

The dish, served chilled in summer, with rosewater, vanilla and cardamom, was "an explosion of yummy tastes you didn't know existed", said Judith Devons, who attended her first Gefiltefest last year. "I was so amazed I had to come back."

Among those admiring the art of Czech strudel chef Michal Hromas were Vivienne Chiswick, from South Moreton in Oxfordshire, and her friend from Borehamwood, Angela Wolfson. "The pastry should be so thin that you should be able to read the newspaper underneath," Ms Wolfson said. "But he said his father didn't like that because it made the newspaper greasy."

Outside the JC hospitality tent, where visitors could sample Gamla rosé or Antonio Russo parev ice-cream, Pinner sisters Jessica Levy, eight, and Charlotte, 10, were slicing oranges. "We're making non-alcoholic Pimm's," they said.

Nearby, Yitzchak Subtee, 16, and some fellow Hasmonean High pupils were showing what they had learned on an LJCC chocolatier course, selling chocolate layer cake and truffles.

At the Kosher Deli barbecue, Grahame Tucker introduced some new products for the summer grill including a whole, spatchcocked chicken in peri-peri sauce and pre-tenderised steaks. "Before the only decent steak you could barbecue was a rib-eye," he said, "This is a flat-iron steak, an old-fashioned cut we are reintroducing which comes from the blade."

The tenderising process perforated the meat, he noted, "so it's very easy to marinade. You can soak it for half an hour."

Israel Ambassador Daniel Taub and Mock The Week creator Dan Patterson took part in one panel discussion. And while Golders Green Synagogue's Rabbi Harvey Belovski explored the kashrut of giraffes - using an inflatable model - Rabbi Natan Levy, co-chairman of the Jewish Social Action Forum, looked at civet coffee.

The coffee, which some believe is the finest in the world, comes from beans which are eaten and then secreted by civets, a species of wild cat. "The question is: Can you eat coffee which comes out of faeces of an animal?" Rabbi Levy said. "Most poskim [interpreters of Jewish law] say yes."

But because coffee-producing civets are often kept in cages, there were ethical problems with the product, he added. "I tried to convince Gefiltefest to buy a civet off eBay. They are about £100."

Ethical eating was also important to Seth Belson, who was selling the Happylands brown and white free-range eggs produced by the flock of 60 hens he and his wife Fiona keep in Edgware. "We've been doing the eggs for about five years," he said, "more out of principle than anything else because we are opposed to battery farming. It's incompatible with Judaism for animals to be treated that way."

While there was a serious side to some sessions, most would have agreed with Joan Nathan that the event was "a lot of fun".

Brandishing a bowl of Mr Hovav's freshly-made salads, Hilary Brass from Bushey said: "We've got a baby-naming for our new grand-daughter Millie soon and I am going to use his recipes."

The Gefiltefest-JC food awards went to Carmelli (best bagel); Daniel's (best challah); Parkway (best cheesecake); Kosher Deli (best butcher); Zest (best restaurant); Pita (best falafel); and Sami's (best shwarma).