Heat oven to 450 degrees F. Rinse the tilapia fillets and pat dry with a paper towel. If desired, cut the fillets lengthwise along the seam in the middle.
In a flat baking dish big enough to hold the fillets in a single layer, melt the butter. Stir in the salt, any cayenne, and grated peel. Place the tilapia pieces in the dish, turning over once to make sure both sides are coated with the butter mixture. Bake, uncovered, in oven for 10 to 20 minutes, depending on size of fillets, until an internal temperature of at least 145 degrees F.
Nichola’s adaptation, after she found the often recommended citrus juice gives tilapia an unpleasant taste of ammonia.http://macheads2.net/recipes/TilapiaCitrusPeelButter.html