01 - In a shallow bowl, whisk together buttermilk and hot sauce. Add catfish fillets, turning to coat thoroughly. Marinate in the refrigerator for a minimum of 15 minutes.
02 - In a separate bowl, whisk together cornmeal, flour, Cajun seasoning, paprika, garlic powder, salt, and black pepper.
03 - In a large skillet or deep fryer, heat 1 inch of vegetable oil to 350°F.
04 - Remove catfish from the marinade, allowing excess liquid to drip away. Coat each fillet thoroughly in the cornmeal mixture, pressing gently to ensure even adhesion.
05 - Working in batches, fry fillets for 3 to 4 minutes per side until golden brown and cooked through. Drain on a wire rack or paper towels.
06 - In a bowl, combine mayonnaise, dill pickles, capers, lemon juice, Dijon mustard, and fresh parsley. Mix thoroughly and season with salt and pepper to taste.
07 - Arrange fried catfish on serving plates while hot and serve with tartar sauce on the side.