If you like your tomato sauce chunky, skip the blending or processing step and serve it hot from the pan. If you like, add meatballs to the sauce.
Simmering Sauce
To achieve the desired consistency, bring the sauce ingredients to a boil, then reduce the heat and simmer uncovered, stirring now and then. This allows the excess liquid to evaporate and the flavors to become concentrated. When the tomatoes are broken down and the sauce is no longer runny, the sauce is done.
Blending Sauce
Purée about half of the sauce in a blender or food processor. Return to the saucepan; add snipped herbs (fresh herbs are added at the last minute to preserve their fresh flavor). Cook 5 minutes more.