1 1/2 tbsp. butter
1/4 c. all-purpose flour
3/4 tsp. dry mustard
1/8 tsp. cayenne pepper
3 c. skim milk
1 1/4 c. shredded sharp Cheddar cheese, divided
1/4 c. shredded Swiss cheese
1/8 tsp. black pepper
5 c. elbow macaroni, cooked

Melt butter in large, heavy saucepan over low heat. Add flour, mustard, and cayenne. Cook 1 minute, stirring constantly with wire whisk. Gradually add milk; stir well. Cook over medium heat 10 minutes or until thickened and bubbly, stirring constantly; remove from heat.

Stir in 3/4 cup Cheddar cheese, Swiss cheese, and pepper, stirring until cheese melts. Stir in cooked macaroni; spoon into 2 quart casserole. Sprinkle with remaining Cheddar cheese. Cover and bake at 350 degrees for 30 minutes. Uncover; brown for 10 minutes. Let stand for 5 minutes before serving.