How to Make It
Heat the olive oil in a large, deep skillet. Add the pancetta and cook over moderately high heat, stirring frequently, until the fat is rendered and the meat begins to brown, about 4 minutes. Increase the heat to high, add the onion and cook until softened, about 2 minutes. Stir in the plum tomatoes, tomato paste and the chile and cook the sauce over moderate heat, stirring occasionally, until thickened, about 3 minutes. Cover and remove from the heat.
In a large pot of boiling salted water, cook the spaghetti until al dente. Drain the pasta, reserving 1/2 cup of the cooking water. Add the spaghetti and the Parmigiano and Romano cheeses to the sauce and toss over moderate heat, adding small amounts of the reserved pasta cooking water until the sauce is thick and creamy. Transfer the pasta to a large shallow bowl and serve at once.