Most recently the author of “Feast: Food of the Islamic World,” Anissa Helou grew up in Beirut with a Syrian father and Lebanese mother, and wrote her first book about Lebanese food in 1994. Now, she lives in Sicily (“It has everything that I was brought up with: seasonality, sunshine, the sea, lovely people, hospitality. But there is no ISIS,” she explains), but she’s still writing about the food of the Islamic world — “Feast” collects recipes from Muslim cultures ranging from Indonesia to Iran and India to Qatar. At Now Serving, Helou talked with Evan Kleiman about her research tactics, her favorite biryani recipe, and a one-time plan to make lardo from a camel’s hump.