In a large saucepan or Dutch oven over medium-high heat, add beef, sausage, and onion and cook until mostly browned, about 5 minutes. Drain if desired. Stir in garlic until fragrant, about 30 seconds.
Stir in crushed tomatoes, tomato sauce, tomato paste, sugar, basil, Italian seasoning, fennel seeds, and bay leaf. Simmer uncovered for 30 minutes, stirring occasionally. Season to taste with salt and pepper (I like 1 teaspoon salt and 1/2 teaspoon pepper).
Ground meat: You can do 2 pounds of ground beef, 2 pounds of ground Italian sausage, or 1 pound of each.
Sugar: Even a tablespoon is too much for some people. If you don’t like the sound of sugar in your meat sauce, please leave it out. In my family, people add ¼ cup or even up to ½ cup.
Fennel seeds: The seeds make the Italian sausage flavors pop. If you love the taste of a sweet tomato sauce, use just ground beef (no sausage), at least ¼ cup sugar, and omit the fennel seeds.
Yield: This recipe makes 2 quarts (8 cups), enough for 16 servings, 1/2 cup each.
Storage: Store leftovers covered in the refrigerator for up to 4 days.
Freezer: The sauce can be cooled and packed into freezer-safe containers (I like glass pint jars). Leave 1/2-inch headspace for expansion. Label, date, and freeze for up to 3 months. Thaw overnight in the refrigerator.