1. Tonnarelli is a square noodle often made with eggs; many Roman cooks prefer tonnarelli for the peppery pasta dish called cacio e pepe (see ** Cheese and Pepper Pasta**) and for partnering with certain tomato-based sauces.
2. The hollow noodle known as bucatini, a dried pasta made from durum wheat and water, is among the most classically Roman shapes; in the dish known as bucatini all’amatriciana (see ** Bucatini all’Amatriciana**), it is paired with a tangy tomato sauce.
3. Gnocchi, whose name literally means “little lumps,” are dumpling-like pastas made, variously, from potatoes, semolina flour, or even spinach and ricotta; in Rome you’ll find plump gnocchi like the ones above, as well as gnocchi alla romana, which are usually flat disks or squares (see ** Gnocchi Alla Romana**).
4. Spaghetti can hardly be called a regional food anymore, but in Rome it is quasi-sacred, especially in that luscious cheese-and-egg-sauce pasta dish, spaghetti alla carbonara (see ** Spaghetti alla Carbonara**).