The recipe yield is:
Saute garlic and onion in oil until onion is transparent. Remove garlic. Add tomatoes, bring to boiling point, then simmer for 1/2 hour. Add tomato paste, diluted with 3 cans water, simmer for at least 1 hour. Add parsley, basil, and oregano to taste and simmer a few minutes longer. Coat zucchini slices with flour and saute lightly in oil. Layer zucchini in baking dish, cover with sauce then parmesan cheese. Repeat until all zucchini is used. Top with mozarella cheese. Cover & bake about 30 min. at 350. Uncover last 15 min.