01 - Gently pat the catfish fillets dry with paper towels to remove excess moisture. Brush both sides of each fillet evenly with olive oil.
02 - In a small bowl, combine paprika, smoked paprika, garlic powder, onion powder, dried thyme, dried oregano, cayenne pepper, black pepper, and salt. Mix thoroughly to create a uniform spice blend.
03 - Generously sprinkle the prepared spice mix over both sides of each catfish fillet. Gently press the spices into the fish to ensure even adherence.
04 - Place a large cast iron skillet over medium-high heat. Allow the skillet to heat until it is very hot, approximately 2-3 minutes, and just begins to smoke faintly.
05 - Carefully add the seasoned catfish fillets to the dry, hot skillet. Cook for 3-4 minutes per side, or until the fish is opaque throughout and flakes easily when tested with a fork. Avoid overcrowding the pan; cook fillets in batches if necessary.
06 - While the catfish cooks, melt the unsalted butter in a small saucepan over low heat. Stir in the lemon zest, fresh lemon juice, and finely chopped fresh parsley. Remove the saucepan from the heat once combined.
07 - Transfer the blackened catfish fillets to individual serving plates. Drizzle generously with the warm lemon butter sauce. Garnish with additional fresh parsley if desired, and serve immediately.