Preheat oven to 350 degrees. Place tortillas on a large baking sheet and bake 10-15 minutes until tortillas are dry and crisp. When cool enough to handle, crumble into small pieces. Heat oil in a heavy saucepan. Saute onions until translucent. Add green pepper and continue until softened and onions are golden. Stir in tomatoes and seasonings, and simmer over low heat for 10 minutes.
Oil a 9 x 13 inch shallow casserole and layer as follows: half the tortillas, half the tomato sauce, half the black beans, half the zucchini and half the cheese. Repeat. Bake for 25-30 minutes until the cheese is bubbly. Let stand for 5-10 minutes. Then cut into squares and serve at once. Serves 6-8. Note: Have torn lettuce pieces, chopped tomatoes, chopped onions and taco sauce on the side.
