I fix this on a regular basis in a cast iron skillet but you can also fix on the grill.

Pat crappie fillets dry. Sprinkle both sides liberally with blackened fish seasoning (whichever brand you like) and press into fillets.

Get skillet smokin hot and add just enough oil to coat the bottom and plop in a couple 2 tbsp. of butter.

Place fillets in skillet and don't move them or they'll stick. Give em about 3-4 minutes on one side, then turn over. They cook quick, so keep an eye on them. When they're almost done, give them a splash of lemon juice. Yum, Yum.