This is how I cook my Stripers and Bluefish. I will cook bluefish only this way and the bass are usually blackened and on occasion baked with dill weed.
First, put the fillets in the freezer to chill while you mix up the spices. Turn on the propane barbeque on HIGH. Place a well seasoned (with high temp oil) cast iron pancacke griddle on the grill and close it to heat up ( 15 minutes) I then mix the spices in a small bowl, spooning them into a shaker top glass jar when done. (for parmesan cheese) Measure and mix 1 ts cayene pepper, 1 ts black pepper, 1 ts white pepper, 1 ts paprika. 2 ts salt, 1 ts ground cumin, 1 ts ground thyme, 1 ts garlic powder, 1 ts onion powder, 1 ts ground oregano. Melt 3-4 tbs butter in the microwave and when done set aside. take the chilled (not frozen) fillets out of the freezer and dip your fingersinto the melted butter and spread a glaze over the fish on both sides. Sprinkle the blackening seasoning over ONE side of the fish and carry out to the grill. Place the fish on the super heated griddle and sprinkle the seasonming on the other side and close the lid on the barbeque. After 3-4 minutes open and turn the fish over for about 2-3 minutes more. It will have made a wonderful spicy crust on the bluefish and a nice blackening to the bass. Serve with tartar sauce and corn on the cob. AWSUM !!!