Arrange fish in single layer on baking sheet lined with foil or parchment paper; set aside.
In a bowl, stir together mayonnaise, lemon rind, pepper and salt; spread over fish.
Top with bread crumbs if using.
Broil fish about 8 inches (20cm) from heat until golden brown on top about 5 minutes. Reduce oven to bake at 500 degrees F until fish flakes easily when tested, another 4 to 5 minutes.
Serve with lemon wedges, rice on the side and a green salad for a delicious summer meal.