1/4 cup butter
1/4 cup all-purpose flour
1/8 teaspoon paprika
1/2 teaspoon dry mustard
1/8 teaspoon black pepper
2 cups milk
1/3 cup cooking sherry (optional)
1 cup shredded cheese - any combination of swiss, cheddar, mozzarella, etc
Stir in the cheeses until melted and well blended.
Serve over broccoli or your favorite vegetables.