The cooking method that coats fish in spices and sears it in hot butter is blackening.
In the classic technique, fish is dipped in melted butter and coated with a strongly seasoned spice mixture. It is then cooked in an extremely hot cast-iron skillet. The heat chars the spices and browns the milk solids in the butter, creating the method’s distinctive dark crust and intense aroma.
Blackening is closely associated with Cajun cuisine and was invented and popularized by chef Paul Prudhomme. His signature preparation used redfish, also called red drum, a Gulf Coast species. The method became famous in the 1980s, when blackened redfish appeared on restaurant menus and in cookbooks across the United States.
Blackening is often confused with grilling, frying, or simply overcooking food until it burns. Those terms describe different processes. Blackening specifically refers to the combination of butter, a spice coating, and very high skillet heat. Although fish is traditional, the same technique can be applied to foods such as chicken, steak, and tofu.