Grisciano, Rieti province, Lazio — a small town in the mountains between Rome and Amatrice. The shepherds' pasta — guanciale (from the pigs they kept), Pecorino (from the sheep they herded), pepper. Predates amatriciana (which did not exist before the New World tomato arrived in Italy).
Gricia (or amatriciana in bianco) is the foundational Roman pasta: guanciale rendered in its own fat with black pepper, finished with pasta water to emulsify and Pecorino Romano. No tomato, no onion, no garlic. It is often called the predecessor of both carbonara (to which egg yolk is added) and amatriciana (to which tomato is added). The guanciale fat is the sauce. The technique of rendering guanciale and using its rendered fat as the base — rather than discarding it — is the structural principle of the entire Roman pasta tradition.
Guanciale fat has a sweet, pork-lard richness different from belly fat — slightly nutty, with more depth. Emulsified with pasta water, it coats the pasta in a thin, glossy film rather than pooling oilily. Pecorino's salt and sharpness balance the fat. Black pepper is the only other flavour. The dish is minimal in components, maximal in result.
Guanciale (cured pork cheek — not pancetta, not bacon) is cut into 1cm × 2cm strips or lardons and cooked in a cold, dry pan over low-medium heat until the fat has fully rendered and the guanciale is translucent and slightly chewy but not yet crisp — about 8-10 minutes. Remove the guanciale, leave all the fat in the pan. Deglaze with a splash of dry white wine (some Romans use water), reduce, then add al-dente pasta and pasta water, toss to coat in the emulsified fat. Return the guanciale, add Pecorino and black pepper, toss off heat.
Rigatoni or spaghetti are both traditional. The pasta water emulsification technique here is the same as carbonara and cacio e pepe — always off heat, always with pasta water. The Pecorino quantity should be substantial: 40-50g per serving. The finished pasta should be visibly glossy from the emulsified guanciale fat.
Using pancetta or bacon — the flavour is entirely different; guanciale's fat has a specific sweetness and texture that is the point of the dish. Cooking guanciale until crisp — it should be tender, not crunchy; the fat should be rendered, not fried away. Adding cold Pecorino directly to the hot pasta without pasta water — it clumps. Onion or garlic in gricia — not traditional.
Ada Boni, La Cucina Romana; Rachel Roddy, Five Quarters