1 (8 oz.) pkg. macaroni, cooked
1 can mushroom soup
1/2 c. milk
1 can mushrooms, sliced
3/4 c. mayonnaise
1/4 c. chopped pimentos (optional)
3/4 lb. grated cheese
1/4 c. chopped onion

Mix all together and pour into large casserole. Crumble Cheez-It crackers and top casserole. Cook 30 minutes at 350 degrees.