The pasta is cooked in moderately salted boiling water. The guanciale is briefly fried in a pan in its own fat. A mixture of raw eggs (or yolks), grated Pecorino romano and a liberal amount of ground black pepper is combined with the hot pasta either in the pasta pot or in a serving dish, but away from direct heat, to avoid curdling the egg. The fried guanciale is then added, and the mixture is tossed, creating a rich, creamy sauce with bits of meat spread throughout. Although various shapes of pasta can be used, the raw egg can only cook properly with a shape that has a sufficiently large ratio of surface area to volume, such as the long, thin types fettuccine, linguine, tagliatelle or spaghetti.
