Pat the catfish fillets dry with paper towels. Place them in a shallow dish or zip-top bag. In a bowl, whisk together buttermilk, hot sauce, 1 tsp kosher salt, and 1 tsp black pepper. Pour the buttermilk mixture over the fillets so they are fully coated. Cover or seal and refrigerate for 30 minutes to 2 hours (30 minutes if short on time, up to 2 hours for more flavor and tenderizing).

Dredge / Breading

Mix Dry Breading

While fish marinates, in a wide, shallow bowl or rimmed baking sheet combine 1 cup cornmeal, 1/2 cup all-purpose flour, 1/2 cup fine cornmeal (or fine polenta), 1 tsp garlic powder, 1 tsp onion powder, 1 tsp smoked paprika, 1/4 tsp cayenne, 1/2 tsp dried thyme, 1 1/2 tsp kosher salt, and 3/4 tsp freshly ground black pepper. Whisk thoroughly so spices are evenly distributed.

Dredge the Fish

Remove fillets from the buttermilk, letting excess drip off for a few seconds. One at a time, press each fillet into the breading mixture, coating both sides and gently pressing to help the breading adhere. Shake off any excess and place on a wire rack set over a sheet pan. If you prefer extra crunch, allow coated fillets to rest on the rack for 10–15 minutes to set the crust before frying.

Frying and Finish

Heat Oil

Pour about 3–4 cups neutral oil into a heavy, deep skillet or Dutch oven to reach roughly 1 to 1.5 inches depth (about 3–4 cups depending on pan size). Heat over medium-high until the oil reaches 350°F (175°C). If you don't have a thermometer, test with a small pinch of breading — it should sizzle and brown gently within 30–45 seconds.

Fry the Catfish

Working in a single layer and without crowding the pan, carefully lower fillets into the hot oil using tongs or a slotted spoon. Fry 3–5 minutes per side (depending on thickness) until golden brown and an instant-read thermometer inserted into the thickest part reads 145°F (63°C). Flip once halfway through to ensure even color. Adjust heat as needed to maintain 325–350°F; if oil browns too quickly, reduce heat.

Drain and Season

Using tongs, transfer fried fillets to a wire rack set over a sheet pan or to a plate lined with paper towels to drain. Immediately sprinkle lightly with a pinch of kosher salt. Let rest 2–3 minutes to finish cooking and to firm the crust.

Garnish and Serve

Serve the fried catfish hot with lemon wedges and a sprinkle of chopped parsley if using. For baskets or sandwiches: place a piece of catfish on buns with shredded lettuce, sliced tomato, and tartar sauce or remoulade. Serve with fries, coleslaw, or hushpuppies as desired.

Sides and Serving (Optional)

If serving with buns and toppings, toast buns lightly in a dry skillet or in the oven for 1–2 minutes. Assemble sandwiches just before serving so the breading stays crisp. Offer tartar sauce, lemon wedges, and any sides family-style.