This humble pasta dish with the nearly unpronounceable name comes from the town of Amatrice in Abruzzo. It is traditionally made with guanciale, but we like it just the same with pancetta. It should be quite spicy—not inedible, but hot. If a little sweat forms on your brow, you know you've made it well.
Place a large sauté pan over medium-high heat and add the pancetta to the pan in one layer. Cook for 5 - 8 minutes, allowing the fat to render out and the pancetta to crisp on all sides. Remove the pancetta and drain off a bit of the fat from the pan - you want to leave about 3 tablespoons. If you don't have this much, add a bit of olive oil.
Add the red onions and fresh chiles or crushed red pepper and sauté until golden brown. Add the garlic and cook for 1-2 minutes. Add the pancetta back to the pan and add the tomato sauce. Simmer for a few minutes to allow the flavors to mingle.
Cook the bucatini in salted boiling water until just short of done. Remove and add directly to the pan of sauce, along with a ladleful of the pasta water. Crank the heat to high and toss together until the sauce coats the pasta. Turn off the heat, stir in the basil and some grated Parmigiano-Reggiano and serve immediately.