Roman Pizza al Taglio

Rome's everyday slice comes from long rectangular trays like these at La Renella, a bakery in Trastevere. You point, the counter cuts a piece to the size you want, and it is weighed and priced by weight. The dough is airy and focaccia-like underneath with a crisp bottom, which lets it carry anything from a plain potato topping to ham and fresh mozzarella added after the bake.