8 ounces elbow macaroni, cooked
2 cups (8 ounces) shredded Cheddar cheese
1 (10 3/4-ounce) can cream of mushroom soup, undiluted
1 cup mayonnaise
1 (4-ounce) can sliced mushrooms, drained
1/4 cup chopped green bell pepper
1/4 cup chopped onion
1 cup round buttery cracker crumbs

Combine first 7 ingredients. Pour into a lightly greased 2-quart baking dish; top with cracker crumbs.

Bake, covered, at 350° for 20 minutes. Uncover and bake 10 minutes.