2 pounds firm ripe tomatoes, cored and cut into 1-inch pieces or two 28-ounce cans peeled, whole Italian plum tomatoes
Salt and freshly ground pepper to taste
In a large saucepan set over moderate heat cook the onion, garlic and oil, stirring occasionally for 5 minutes. Add the tomatoes and salt and pepper. Simmer, covered, stirring occasionally for 20 minutes. If desired, puree the mixture in a food processor or blender or through the disk of a food mill.