Preheat broiler. Grease a broiling pan. In a small bowl, mix together the parmesan cheese, butter, mayonnaise and lemon juice. Season with basil, pepper, onion powder and celery salt. Mix well and set aside.
Arrange fillets in a single layer on the prepared pan. Broil a few inches from the heat for 2 to 3 minutes. Flip the fillets over and broil for 2 more minutes. Remove the fillets from the oven and cover them with the parmesan cheese mixture on the top side. Broil for 2 more minutes or until the topping is browned and the fish flakes easily with a fork.