1. Preheat broiler.
2. Combine first 6 ingredients in a shallow dish. Coat both sides of fish with cooking spray. Dredge fish in cornmeal mixture.
3. Place fish on a broiler pan coated with cooking spray. Broil 10 minutes or until desired degree of doneness.
4. Combine butter, rind, and juice in a small bowl; stir well.
5. Spread 1 teaspoon butter mixture over cut side of each of 4 bread tops. Place 1/4 cup lettuce, 2 tomato slices, and 1 fillet on each of 4 roll bottoms. Place top halves of rolls on sandwiches.
Coating the broiler pan with cooking spray is an important step to ensure the coating stays on the fish, not stuck to the pan. Be sure not to overcrowd the pan either. Overcrowding can hinder evaporation as the food cooks, creating steam and ultimately a soggy crust.