In a large, heavy pot, saute onions in olive oil, adding more olive oil if necessary.
When onions are almost clear, add garlic and continue to Saute.
Add tomatoes, tomato paste, water, bell pepper and seasonings. Cook over 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 for 1 hour.
Brown ground beef and sausage, if desired, in a skillet.
Drain fat and add to gravy. Simmer for at least 1 hour.