3–4 small hot peppers such as calabrian, chopped or 1 tablespoon of hot red pepper flakes
1 medium yellow onion, diced
1 28 ounce can of imported Italian tomatoes, preferably San Marzano (look for the DOP)
salt to taste
1 pound penne pasta
freshly grated pecorino-romano cheese for serving
Heat the olive oil in a large sauté pan over medium heat.
Add the guanciale and cook, stirring, until the fat starts to render and the guanciale is lightly browned.
Stir in the hot pepper and cook for about 1 minute, then add the onions and cook, until they are soft and translucent, about 8 minutes.
Using your hands crush the tomatoes in a bowl, and then add them to the pan. Fill the empty tomato can about halfway with water and pour the water in with the tomatoes, season with salt to taste and stir.
When the tomatoes come to a boil, turn the heat down to a simmer and let the sauce cook, stirring occasionally, until thickened about 20 minutes.
Meanwhile bring a pot of generously salted water to a boil and add the pasta, cook until al dente.
Drain the pasta, add it back into the pot and stir in enough of the sauce to coat the penne well.
Dish the penne out into serving dishes, top with a little more sauce and serve with freshly grated pecorino-romano for sprinkling on the pasta.