Using the flat side of a knife, mash garlic and salt together to form a paste. In bowl combine garlic paste, mustard, lemon juice and horseradish. Sprinkle both sides of fillets with pepper. Transfer fillets to a broiler rack that has been sprayed with Pam.
Using a pastry brush, brush mustard mixture evenly over one side fillets. Broil approximately 5 minutes or until fish flakes easily at the touch of a fork. Serves 2. Serve with 1 cup tossed salad. Single serving = 4 ounces protein.