Pre-heat oven to 350. Cook onions in olive oil over medium heat until tender. Add garlic and chili powder and cook for 30 seconds. Add in black beans and corn until heated. Add 12 oz of pizza sauce. Layer ingredients in a small baking dish starting with half of left over sauce. Add tortilla, tomato mixture, cheese then start over again. Ending with leftover pizza sauce and a good helping of cheese. Bake for 20 minutes.
