1/4 c. butter
1 lb. mushrooms, sliced
1/2 c. chopped celery with leaves
1/4 c. finely chopped onion
3/4 c. milk
1 can cream of mushroom soup
1/2 tsp. salt
1/4 tsp. pepper
3 c. soft bread cubes
4 oz. shredded sharp Cheddar cheese (1 c.)
1 (6 oz.) can sliced water chestnuts, drained
1/2 c. mayonnaise
3 eggs, separated

Cook and stir mushrooms, celery, onions in butter until tender, about 5 minutes. Heat milk, soup and bread cubes just to boiling in large saucepan, stirring frequently. Reduce heat and add cheese. Cook and stir over low heat until cheese is melted. Remove from heat. Stir in water chestnuts, mayonnaise, salt, pepper, egg yolks and mushroom butter mix into soup mix.

Beat egg whites until stiff. Fold gently into mushroom soup mix. Pour into ungreased 11 x 7 x 1 1/2 baking dish. Bake 1 hour at 325 degrees or until knife inserted in center comes out clean.

Great fool proof souffle - can all be prepared in advance up to egg whites. Fold in - thrown in oven during cocktail hour!