Put onion, zucchini, celery, olives and garlic into a food processor to chop up vegetables to desired size.
In a large frying pan or pot, warm up the olive oil. Add processed vegetables stirring for 5 minutes.
Stir in the tomatoes, beans, salt, couscous and Parmesan.
Spray a 10x10 casserole dish and heat oven to 350 degrees. Spoon mixture into casserole dish and cover with cheddar and bread crumbs. Cover dish with aluminum foil. Bake for 15 minutes. Remove aluminum and continue baking for and additional 15 minutes.