3 T butter
3 T all-purpose flour
1/4 tsp ground mustard
dash cayenne pepper (if desired)
1 cup milk
1 cup shredded Cheddar or Swiss cheese
4 eggs, separated
In a saucepan, melt butter. Stir in the flour, mustard and cayenne until smooth; gradually add the milk. Bring to a boil; cook and stir for 1-2 minutes or until thick. Reduce heat; stir in cheese until melted. Remove from the heat. Stir a small amount of hot mixture into egg yolks; return all to the pan, stirring constantly. Cool slightly.