Bucatini all` amatriciana

3 pounds fresh or canned tomatoes, coarsely chopped
1 tablespoon olive oil
1 pound pancetta, cut into pieces 1/4 inch thick by 1 inch long
1 cup diced onion
1 cup white wine
2 1/2tablespoons minced fresh chili pepper, seeds removed (3 medium)
1 teaspoon dried red pepper flakes
1/2 cup sliced fresh basil leaves, plus 4 sprigs
1 1/2cups finely grated Pecorino Romano
1 teaspoon kosher salt
freshly ground black pepper
3/4 pound Bucatini or Perciatelli

1. In a 3 quart non-reactive saucepan heat the tomatoes over medium heat until juicy, about 5 minutes. Pass the tomatoes through a food mill to remove their seeds and skins. You will have about 5 cups of tomato puree, reserve.
Wipe the saucepan clean and return to medium heat. Add the olive oil and the pancetta, stirring until the pancetta is crisp, about 15 minutes. Remove the pancetta with a slotted spoon and reserve.
2. Pour off all but about 2 tablespoons of fat from the pan. Add the onions and cook over medium heat until golden, about 5 minutes. Pour in the white wine, and reduce by 3/4. Add the pureed tomatoes, chili pepper, and red pepper flakes. Simmer gently for 30 minutes, stirring occasionally with a wooden spoon.
3. Add the reserved pancetta, basil, and 3/4 of the Pecorino Romano. Season with salt and pepper. Simmer for an additional 15 minutes, stirring occasionally to prevent the cheese from sticking to the bottom of the pan. (May be prepared up to this point, and frozen for future use).
4. Bring 1 gallon of water to a boil and add 1 tablespoon of salt. Cook the Bucatini al dente. Toss with the sauce, transfer to a warmed bowl, and serve, sprinkled with the remaining cheese and garnished with the basil sprigs.