Directions:

In a bowl, combine broth, mustard, lemon juice and pepper. Pour 1 cup broth mixture into a large shallow nonmetallic dish. Add fish and turn to coat. Cover and refrigerate 1 hour, turning fish occasionally. Remove fish from marinade. Grill or broil 10 minutes or until fish is done, brushing with marinade and turning often. In saucepan, mix cornstarch and remaining broth mixture. Bring to a boil; cool 2 minutes until thickened, stirring constantly. Serve with fish.