Salsa di Pomodoro

• 1 can (28 ounces) plum tomatoes, with their juices
• ½ cup tomato purée

Place the tomatoes and their juices in a food processor and process until finely chopped but not liquefied. Transfer to a heavy saucepan. Stir in the tomato purée and place over low heat. Bring to a simmer and cook, stirring often, until the sauce is slightly thickened, about 20 minutes. Season with salt and pepper. If desired, stir in the butter or olive oil for a smoother finish, and the suga