Place half the bread crumbs in bottom of casserole. Combine mushrooms with onion, celery, green pepper, mayonnaise, salt & pepper. Pour mushroom mixture over bread crumbs and put remaining bread over the top. Combine beaten eggs with milk. Pour over casserole and let stand in refrigerator overnight. Before baking, pour 1 can mushroom soup over top of casserole. Bake at 325 degrees for 50 minutes. Sprinkle grated cheese over top of casserole 10 minutes before removing from oven.