8 oz. macaroni
1 tsp. butter
1 egg, beaten
3 c. grated sharp cheddar cheese
1 tsp. dry mustard
1 tsp. salt
1 c. milk

Preheat oven to 350 degrees. Cook macaroni according to package directions. Drain well. Reserve a small amount of cheese. Add butter, egg, and remaining cheese to hot macaroni. Mix well. Pour into 1 1/2 quart buttered casserole dish. Mix dry mustard, salt and 1 tablespoon hot water in small bowl. Stir in milk. Pour over casserole. Sprinkle with remaining cheese. Bake 45 minutes or until top is crusty.