01 - Pat the fish fillets dry and place them in a shallow dish. Pour buttermilk over the fillets, turning to coat. Marinate for 10 minutes while you prepare the breading.
02 - In a large shallow bowl, combine cornmeal, flour, Cajun seasoning, smoked paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper. Mix well.
03 - Heat about ½ inch of vegetable oil in a large skillet over medium-high heat (oil should reach 350°F/175°C).
04 - Remove fish fillets from the buttermilk, letting excess drip off. Dredge each fillet in the cornmeal mixture, pressing lightly to ensure an even coat.
05 - Fry the fish in batches (do not overcrowd the pan) for 3–4 minutes per side, or until golden brown and cooked through.
06 - Transfer fried fish to a paper towel-lined plate to drain excess oil. Serve hot with lemon wedges and a sprinkle of fresh parsley, if desired.