In a large, heavy pot, sauté onions in olive oil, adding more olive oil if necessary. When onions are almost clear, add garlic and continue to sauté. Add tomatoes, tomato paste, water, bell pepper and seasonings. Cook on low heat about 3 to 4 hours, stirring occasionally to check that gravy is not sticking to bottom of pot.
Lower heat to simmer, if necessary. Add tomato sauce and more water if gravy is too thick. Simmer 1 hour.
Brown ground beef and sausage, if desired, in a skillet. Drain fat and add to gravy. Simmer at least 1 hour.
Servings: 8 quarts