2 tbsp. butter
2 tbsp. flour
1 c. milk, plus 2 tbsp. reduced fish-poaching liquid
4 (3/4 oz.) slices light American cheese, cut in strips
1 tbsp. pimiento, chopped
1/4 tsp. dry mustard

Microwave butter in 1 quart measure or bowl on high 30 seconds or until melted. Blend in flour. Gradually add milk and poaching liquid, stirring constantly. Microwave three to five minutes or until sauce boils and thickens, mixing well after each minute; continue microwaving one minute. Add cheese; microwave 30 seconds to one minute or until sauce is hot and smooth. Stir in pimiento and dry mustard.