1 lb. elbow macaroni
1 lb. cheddar cheese, grated
1 (10 1/2 oz.) can cream of mushroom soup
1/2 c. mayonnaise
1 (6 oz.) can sliced mushrooms, drained
1/4 c. finely chopped onion
2 tbsp. chopped pimento
2 tbsp. chopped green pepper
1/4 tsp. ground black pepper

Cook macaroni according to package directions; drain but do not rinse. Combine macaroni, cheese, soup, and mayonnaise. Mix well. Stir in mushrooms, onion, pimento, green pepper, and black pepper. Heat mixture, stirring until heated throughout or turn into a 2 quart greased casserole and bake in preheated 350 degree oven for 30 minutes, or until bubbly.