Rigatoni all'Amatriciana

In a large saucepan, cook the rigatoni until al dente. Drain the pasta, reserving 1 cup of the cooking water.

Meanwhile, in a large saucepan, heat the olive oil. Add the bacon and onion and cook over moderately high heat, stirring occasionally, until the onion is softened and the bacon is browned, 5 to 7 minutes. Add the tomato paste and crushed red pepper and cook, stirring, for 1 minute. Stir in the strained tomatoes and bring the sauce just to a simmer.

Add the pasta and reserved cooking water to the sauce and cook over moderate heat, tossing, until the pasta is coated. Remove from the heat and stir in the 1/2 cup each of cheese and parsley. Season the pasta with salt and black pepper and transfer to bowls. Garnish with chopped parsley and serve, passing more cheese at the table.