In a large skillet, saute onions in vegetable oil for 5 minutes. Add green pepper, salt, garlic, oregano and basil. Cook 5 minutes or until green pepper is soft.
Stir in zucchini and cook over medium heat for 7 minutes, adding a few tablespoons of water, if necessary. Stir occasionally.
Add marinara sauce. Bring to a low simmer and cook 10 minutes or until zucchini is tender.