I've spent a lot of time in Rome over the years, including an extended period to research my novel about the great artist Caravaggio, A Name in Blood. Even a writer's got to eat, so here are the unmissable eateries of the eternal city.

1. Sora Margherita. Piazza delle Cinque Scole. Looks like a scene from Fellini's Roma, with rough decor, unrestrained atmosphere, and a focus on good food rather than "fine dining." Order anything, it's great. And don't leave food on your plate. The waitress will make you finish it.

2. San Crispino, Piazza della Maddalena and Via della Panneteria. Ice-cream is usually displayed in Rome in massive piles that are supposed to make it irresistible. At San Crispino, they keep the ice-cream under silver covers. But the taste truly is impossible to resist. The house flavor is honey, but the selection is always different. One day there'll be whisky, the next you'll find licorice. I've heard people complain that it's expensive. But as Martin Cruz Smith once said, "You don't sell a ride on a rocket shit for a dollar."

3. Il Fornaio. Via dei Baullari. Near Campo de'Fiori, this bakery/deli has excellent pizza and savories. But if you'd like a sugar-high that won't give you a gelato head-freeze, this is the place. The torta con ricotta e ciocollata is officially designated "the best thing in the world" by my five-year-old son.

4. Obika Mozzarella Bar. Campo de'Fiori, and Piazza Firenze. A chain that has expanded into the UK and USA. But there's nowhere to enjoy it that's better than Rome. A tasting menu of several different mozzarellas comes with a lesson from the staff about what makes a good mozzarella. (If you press it and thin white liquid comes out, it's fresh; if not, blaaah.) Also a great place for morning espresso and pastry.

5. Osteria della Quercia. Piazza della Quercia. In a tiny piazza opposite the Renaissance palazzo where the Council of State sits, in the shade of the oak tree from which it takes its name. A great place for traditional Roman food like deep fried cod and artichokes.