Macaroni & Cheese Jan Peterson

2 cups uncooked macaroni 1/4 cup butter

½ cup flour 1 ½ cups milk

1 ½ cups sour cream 1 tsp salt

½ tsp pepper ½ tsp. dry mustard

2 ½ cups sharp Cheddar cheese 1/4 cup Parmesan cheese

Cook macaroni in salted boiling water. Drain and rinse with cold water. Pour into a 3 quart baking dish. In saucepan, melt butter and stir in flour, Gradually stir in milk and sour cream. Add salt/pepper and mustard. Cook over low heat, stirring constantly, until sauce bubbles and thickens. Toss macaroni with 2 cups Cheddar cheese and Parmesan cheese. Pour sauce over macaroni and mix thoroughly. Sprinkle with remaining Cheddar cheese. Bake, uncovered, for 1 hour or until bubbly and brown.