Heat 2 Tbsp. oil in a heavy medium saucepan over medium heat. Add onions & cook until golden,
stirring occasionally, about 5 minutes. Stir in tomato sauce, garlic, oregano & Italian seasoning.
Simmer until thickened, about five minutes.
Heat remaining 1 Tbsp. oil in skillet over medium deat. Add mushrooms & zucchini & cook until
tender, stirring occasionally, about five minutes. Set aside.
Preheat oven to 350F. Place tortillas on baking sheet & bake until crisp, about 4 minutes. Spread
about 1/4 cup sauce over each. Sprinkle each with 1/4 cup cheese. Top pizzas with mushrooms,
zucchini, peppers & olives. Bake until cheese melts, about 5 minutes. Serve.