01 - Pat the fish fillets dry with paper towels and place them in a shallow dish. Pour buttermilk over the fillets, turning to coat evenly. Let marinate for 10 minutes while preparing the breading mixture.
02 - In a large shallow bowl, combine cornmeal, flour, Cajun seasoning, smoked paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper. Whisk thoroughly until all spices are evenly distributed throughout the mixture.
03 - Pour approximately 1/2 inch of vegetable oil into a large skillet. Heat over medium-high heat until the oil reaches 350°F, maintaining this temperature throughout the frying process.
04 - Remove fish fillets from the buttermilk, allowing excess liquid to drip off. Dredge each fillet in the cornmeal mixture, pressing lightly to ensure an even, thick coating adheres to all sides.
05 - Fry the fish in batches, avoiding overcrowding the pan. Cook for 3 to 4 minutes per side until golden brown and completely cooked through. The internal temperature should reach 145°F.
06 - Transfer fried fish to a plate lined with paper towels to drain excess oil. Serve immediately with lemon wedges and garnish with chopped fresh parsley if desired.