1/2 lb. macaroni
1 sm. onion
2 tbsp. butter
1 tbsp. flour
1/4 tsp. dry mustard
3/4 tsp. salt
2 c. milk
1/2 lb. American cheese
3/4 c. bread crumbs
4 tbsp. butter

Cook macaroni about 10 minutes. Stir often. Drain. Saute onion in butter. Stir in flour, mustard, salt. Slowly add milk. Add 3/4 of the cheese and stir until melted. Pour cooked macaroni into a greased casserole; add sauce and mix lightly. Top with remaining cheese. Melt butter in a skillet. Add bread crumbs. Sprinkle over the casserole. Bake at 400 degrees for 20 minutes.