Step by step

Return the browned pancetta to the pan with the tomatoes and cook for another minute

Tips
If you want to prepare authentic spaghetti all’amatriciana, don’t use onion and, above all, try to get hold of some pork jowl meat instead of pancetta.
Trivia
Spaghetti all’amatriciana is one of the most popular dishes of the Lazio cuisine: its origin is in the town of Amatrice.