1. Heat vegetable oil in a large skillet.
2. Saute/stir the green pepper, onion, mushrooms, zucchini, and garlic in hot oil until crisp-tender.
3. Drain and cool.
4. In a mixing bowl, combine the eggs and ricotta cheese; whisk until well blended.
5. Add in the sauteed vegetables and the remaining ingredients; stir to blend.
6. Pour mixture into a 10-inch springform pan that has been sprayed with non-stick cooking spray.
7. Bake in a 350° oven for 1 hour or until set.
8. Let rest for 10 minutes before cutting.