Step 1

In a large saucepan set over medium heat, melt the butter in the olive oil. When the butter is foaming, add the carrots, celery, onions and garlic, and cook, stirring often, until they have softened, 8 to 10 minutes.

Step 2

Stir in the parsley and tomatoes, crushing them with your hands or with the back of a slotted spoon as you add them to the pan. Bring the sauce to a boil. Season to taste with salt and pepper.

Step 3

Reduce the heat to medium-low and simmer, partially covered, until the tomatoes are sweetened and cooked, about 45 minutes.

Step 4

Variations: To create a less coarse version of this sauce, puree the tomatoes in a food mill or food processor before proceeding with this recipe. Also, 1 pound ground beef may be added to the sauce before the tomatoes. Cook until the beef is lightly browned and then proceed with the recipe.