Bucatini with a Spicy Tomato Sauce

This dish is named after the small town of Amatrice, about 100 miles northwest of Rome, though most people think of it as a classic Roman dish. In Rome it acquired onions and sometimes olive oil, and it is usually made with guanciale (cured pork jowl) rather than pancetta. In the following recipe I use onions, as in Rome; butter, because I like the creaminess it gives the dish; and pancetta, because guanciale is too difficult to find in the States. It’s a sauce I will never tire of; just th