Whisk together 1–2 cups of Buttermilk and a few dashes of Hot Sauce in a shallow dish; season with a pinch of Kosher Salt and Black Pepper. Add the Catfish Fillet, turn to coat, and refrigerate for 30 minutes to an hour to tenderize and flavor the fish.
Meanwhile, make the crispy dredge: in a wide bowl combine 1 cup Fine Yellow Cornmeal, 1/2 cup All-Purpose Flour, 1 tsp Paprika, 1/2 tsp Cayenne Pepper (more or less to taste), 1/2 tsp Garlic Powder, 1 tsp Kosher Salt and 1/2 tsp Black Pepper. Mix well.
Pour enough Peanut Oil into a heavy skillet or Dutch oven to reach about 2 inches deep and heat to 350°F (175°C). If you don’t have a thermometer, test by dropping a pinch of the dredge into the oil — it should sizzle and brown within 30–60 seconds.
Remove the fillets from the bath, letting excess buttermilk drip off. One at a time, press the fish into the cornmeal mixture to coat thoroughly, then carefully lower into the hot oil. Fry until golden and opaque through the center, about 3–5 minutes per side depending on thickness. Transfer to a wire rack set over a baking sheet to drain and keep warm.
For the hush puppies, whisk together 3/4 cup Fine Yellow Cornmeal, 1/2 cup All-Purpose Flour, 1 tsp Baking Powder, 1/4 tsp Baking Soda, 1 tsp Kosher Salt, 1 tsp Sugar and a pinch of Cayenne Pepper. Stir in 1/2 cup finely chopped Onion. In a separate bowl beat 1 Egg with about 1/2 cup Buttermilk, then fold into the dry ingredients to make a thick spoonable batter; adjust thickness with a little more buttermilk if needed.
Return the oil to 350°F (175°C) and drop the hush puppy batter by tablespoonfuls into the hot oil (don’t overcrowd). Fry until deep golden, about 2–3 minutes, turning as needed. Remove with a slotted spoon and drain on paper towels or a rack.
Make a quick tartar sauce by combining 1 cup Mayonnaise with 1/3 cup finely chopped Dill Pickles, 1–2 tbsp Lemon Juice, 1 tsp Dijon Mustard, 1 tbsp chopped Parsley, and a few drops of Hot Sauce to taste. Season with salt and pepper and refrigerate until ready to serve.
Melt 2–3 tbsp Butter and stir in a squeeze of Lemon to make a warm lemon-butter for brushing the fish or serving on the side. Plate the fried Catfish Fillet with hush puppies, a spoonful of tartar sauce, lemon wedges, and a sprinkle of chopped Parsley. Enjoy immediately while everything is hot and crisp.
