Yellow Squash & Onion Casserole

Slice thin yellow squash and onions. Cover bottom of casserole. Dish with a little vegetable oil. Layer as follows: 1) Squash. 2) Spread a little mustard on squash. 3) Onions. 4) Lightly sprinkle bread crumbs. 5) Salt and pepper. 6) Grated cheese. 7) A few dabs of butter. Squash, mustard. Be sure to end with grated cheese and dabs of butter. Cover and bake at 350 degrees for 30-40 minutes, or until squash and onions are tender.