If you need to disguise your fish, non fatty fish can be used in most any recipe for stronger fish as long as you can match the thickness of the fish your recipe calls for. I save this cooking for outside because of the smoke. You need lots of very hot oil, with very cold fish and batter. I put my fish and batter in bowls surrounded by ice to keep them chilled and get the oil hot with a gas burner. Hot oil and cold fish is the key to a crispy coating with less oil saturation.
Fatty fish is considered to be best when broiled, baked, or put on the charcoal grill.
One thing about fish is that you never want to over cook it because no matter how fresh a fish is, if you overcook it and it starts to burn, it will stink like old rotten fish. This is a traditional method for cooking pompano in most of the best restaurants. Pompano is a fatty fish and not for frying. Preheat oven to 450 degrees. Close the parchment paper, fold the edge and bake for 15 minutes until the paper is browned and puffed.