Choose the Right Pan: A cast-iron skillet is your best friend for blackened fish. It holds heat like a champ and gives the fish that delicious char. A heavy stainless steel pan can also work in a pinch if you don't have one.
Crank Up the Heat: High heat is essential. Set your burner to high or medium-high heat, and allow the cast iron skillet to heat up for a few minutes. You'll know it's ready when a drop of water dances on the surface.
Oil the Pan: Add a thin layer of cooking oil with a high smoking point, such as avocado. You don't need a lot, just enough to coat the pan. Excess oil can lead to a greasy crust rather than a clean, crisp, blackened finish.
Place the Fish in the Pan: Carefully lay the fillets in the very hot skillet, seasoned side down. If you're nervous about sticking, swirl the pan slightly as you place each fillet to distribute the oil. Leave some space between pieces so they cook evenly.
Press for an Even Sear: Use a spatula to gently press down on each fillet for the first 10-15 seconds. This helps the spices fully contact the hot pan, forming a consistent crust.
Flip Just Once: Cook the first side for 3-4 minutes or until the edges are crisp and darkened. Flip it gently and give the second side another 2-3 minutes, depending on the thickness of your fish.
Remove and Rest: Once the fish is done, transfer it to a plate to rest for a minute or two. This allows the juices to redistribute, keeping the fillets tender and moist.