1/2 lb. macaroni
1 tsp. butter
1 egg, beaten
3 c. grated sharp cheese
1 tsp. dry mustard
1 tsp. salt
1 tbsp. hot water
1 c. milk

Boil macaroni in water until tender and drain. Stir in butter and egg. Add cheese, leaving enough to sprinkle on top. Pour into buttered casserole dish. Mix mustard and salt with the water and add to milk. Add this mixture to the casserole and sprinkle top with cheese. Bake at 350 degrees for 45 minutes or until custard is set and top is crusty.