2 tbsp. butter
2 tbsp. all purpose flour
1 (13 oz.) can evaporated milk
1/2 c. water
1 tsp. mustard
1 tsp. Worcestershire sauce
1/2 tsp. salt
1/4 tsp. pepper
1/2 lb. shredded pasteurized process American cheese

Place butter in a 4 cup glass measuring cup. Microwave 1 minute until butter is melted. Stir in flour until smooth. Gradually stir in milk and water. Stir in mustard, Worcestershire sauce, salt, and pepper. Cover with waxed paper. Microwave 5-7 minutes on high. Stir twice during cooking. Add cheese and stir until cheese melts. If necessary, microwave 30 seconds to 1 minute.