Roman food centres on four canonical pasta dishes — cacio e pepe, carbonara, amatriciana, and gricia — all built from a small set of ingredients (cheese, guanciale, black pepper, egg) with slight variations. Every trattoria serves them; the question is who does them well. The other Roman staples are supplì (fried rice balls with mozzarella), pizza al taglio sold by weight, and the offal-heavy cucina povera of Testaccio — trippa, coda alla vaccinara, and pajata.
Testaccio is the neighbourhood most associated with traditional Roman cooking, home to the old slaughterhouse that once paid workers in offal cuts. Trastevere has more tourists but still holds good trattorias. Prati, near the Vatican, has neighbourhood restaurants that see fewer visitors. Avoid restaurants that display photographs of food outside or that have touts blocking the entrance.