I got this recipe from All Recipes. My family loves it! (even my 14 month old!) I usully half it and make it for 2 fillets. If your going to do more than that, I would do the entire recipe. I like a lot of cheese! Enjoy!
1/2 cup Parmesan cheese
1/4 cup butter, softened
3 tablespoons mayonnaise
2 tablespoons fresh lemon juice
1/4 teaspoon dried basil
1/4 teaspoon ground black pepper
1/8 teaspoon onion powder
1/8 teaspoon celery salt
2 pounds tilapia fillets
Preheat your oven's broiler. Grease a broiling pan or line pan with aluminum foil.
In a small bowl, mix together the Parmesan cheese, butter, mayonnaise and lemon juice. Season with dried 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 a couple 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 fish flakes easily with a fork. Be careful not to over cook the fish.