Blackening meats and fish is a cooking technique commonly associated with Cajun cuisine. Traditionally, a blackening recipe called for redfish, but today this preparation is used for cooking all types of poultry and seafood. Blackening fish is a quick and straightforward process requiring only a few ingredients, but it must be performed outdoors due to the heavy amount of smoke it produces.
- Heat a dry cast iron pan over medium-high heat. A cast iron pan is a required tool for blackening fish, as other pans aren't capable of delivering the intense heat needed for this preparation. Set the pan onto a charcoal grill or a propane burner set to medium-high heat. Allow the pan to heat for about 10 or 15 minutes, and do not add any oil to the pan.
- Melt some butter in a shallow pan. While the cast iron pan is heating, melt a generous amount of butter on another part of the grill. You will need enough butter to dredge all of the fish through, and more if you want to serve the fish with melted butter for dipping.
- Dredge each fish fillet through the melted butter. Use a pair of tongs to coat each fillet on both sides with the melted butter, shaking off any excess. Set the fillets onto a large dish for seasoning.
- Season the fillets with a Cajun spice mix. Season the fillets to taste by sprinkling them with a Cajun blackening spice on both sides; spice mixes like these can be purchased from the grocery store or made from scratch. Blackening spice mixes typically contain a mix of thyme, oregano, paprika, garlic, onion, ground chili peppers, peppercorns, and salt. You can substitute another type of all-purpose seasoning mix if desired.
- Set the fish fillets into the cast iron pan. Use a pair of tongs to place the fillets into the pan, being careful not to crowd the pan. Do not move the fillets once they have been placed into the pan; by allowing them to sear in place, they will flake away from the pan rather than stick. If the pan has been heated properly, an intense amount of smoke will be generated as the milk solids in the butter char against the fish.
- Turn the fish fillets after 1 or 2 minutes. Once the fillets begin to rise away from the pan, flip them with a spatula. The cooked side should have a thick, blackened crust of butter and spices.
- Remove the fish from the grill. Let the fish cook for another 1 or 2 minutes on the other side, then remove them from the pan. Serve them as desired -- pairing them with lemon and butter is the traditional method.