Makes 2 quarts

1/2 cup extra-virgin olive oil
2 small onions, finely chopped
2 garlic clove, finely chopped
2 celery stalk, finely chopped
2 carrots, peeled and finely chopped
1 teaspoon sea salt
1 teaspoon freshly ground black pepper
2 (28-ounce) cans crushed tomatoes or 3-5 pounds fresh, cored and chopped
2 dried bay leaves

In a large pot, heat the oil over a medium-high flame. Add the onions and garlic and saute until the onions are translucent, about 10 minutes. Add the celery, carrots, and 1/2 teaspoon each of salt and pepper. Saute until all the vegetables are soft, about 10 minutes. Add the tomatoes and bay leaves, and simmer uncovered over low heat until the sauce thickens, about 1 hour. Remove and discard the bay leaves. Season the sauce with more salt and pepper, to taste.

The sauce can be made 1 day ahead.