Caught my first king last weekend and used a recipe I got from an old man in Georgia. It was real good, here it is.
Melt some real butter in a saute pan. Put in at least 1/2 chopped yellow onion. Cook on medium heat until onion is translucent, about 5 minutes. Put in one of the small size containers of sour cream. If you want the full flavor don't use the light kind. Take off the heat and stir it all together real good. Lay out a piece of heave duty foil and spoon some of the mixture on the foil. Lay the fish on top and then put the rest of the topping on that. Seal it up real good and put on a medium hot grill, covered. Turn once just to get the sauce to cook into both sides. I cooked a piece of loin about 1 1/2 thick and 10" long about 8 minutes a side. I did open it up to see if it flaked at the thickest point. All I can say is, we ate the whole thing, it was real good this way.
I still have a lot, some steaks and more fillet too. Anybody have a favorite way to cook it?