Add 1 pound ground Italian sausage or lean ground beef, cooked and drained, to the tomato mixture of the basic recipe.
For added color, flavor and nutrition add 1 (10 ounce) package frozen spinach, thawed and water removed, as another layer after the cheese layers.
Add both Italian sausage and spinach for great nutritional value and appearance. Use each as a layer in the recipe.
Add fresh basil to sauce for added color and flavor or sprinkle fresh basil on top as a garnish.
Use fresh mozzarella cheese, thinly sliced, as an option to shredded mozzarella cheese.