Pat your catfish fillets completely dry with paper towels. Moisture is the enemy of crispiness, so don't skip this step. In a shallow bowl, whisk together your buttermilk, yellow mustard, hot sauce, and fresh lemon juice until smooth and well combined. The mixture should smell bright and slightly spicy. Arrange your dried fillets in a large, shallow dish or zip-top bag and pour the marinade over them, making sure each piece is coated. Cover or seal, then refrigerate for at least 30 minutes but ideally 2-4 hours. This marinade does the work of tenderizing while adding flavor that penetrates the fish, not just sits on top.

While your fish marinates, combine your flour, cornmeal, Cajun seasoning, garlic powder, black pepper, cayenne, and paprika in a wide, shallow bowl. Whisk it together thoroughly—you want the spices evenly distributed throughout. This is your secret weapon for that authentic color and flavor. I like to mix the dry ingredients and let them sit for a few minutes so all the flavors meld together slightly. It's a small step, but it makes a difference. Your coating should smell fragrant and inviting, with no lumps from the seasonings clumping together.

Pour your oil into a large, heavy-bottomed skillet or Dutch oven. You want enough oil so the fillets are at least half-submerged. Place over medium-high heat and let it warm slowly. Use a thermometer—this is non-negotiable. You're aiming for 350°F. If your oil isn't hot enough, the fish will absorb oil and become greasy. Too hot, and the crust will brown before the inside cooks through. While the oil heats, remove your marinated catfish from the refrigerator. Let it sit at room temperature for about 5 minutes so it doesn't cool your oil dramatically when it hits the pan.

Working with one fillet at a time, remove it from the marinade (let excess drip back into the bowl) and dredge it thoroughly in your seasoned cornmeal mixture. Press gently so the coating adheres. Make sure both sides and the edges are covered—this creates that beautiful, crispy exterior that holds in the moisture of the fish. Place each coated fillet on a clean plate or parchment paper. Don't stack them; you want them in a single layer. Let the coated fillets rest for 2-3 minutes so the coating sets slightly. This prevents it from falling off during frying.

Once your oil reaches 350°F, carefully place 2-3 fillets into the hot oil. Don't crowd the pan—each fillet needs space to fry evenly and the oil temperature to stay consistent. Fry for 3-4 minutes per side, until the coating is deep golden brown and crispy. The fish inside should flake easily with a fork and be completely opaque. Use tongs or a slotted spatula to gently turn the fillets halfway through cooking. Listen for that gentle sizzle—it should be steady and satisfying, not a loud, violent bubble (that means the oil is too hot). When done, transfer the cooked fillets to a plate lined with paper towels to drain excess oil. Repeat with remaining fillets, bringing the oil back to 350°F between batches. This is important for consistency—if you fry too many at once or let the temperature drop, your results will be uneven.

Let your fried catfish rest on the paper towel-lined plate for about 2 minutes before serving. This allows the exterior to set and any excess oil to be absorbed. The fish will continue to cook slightly from residual heat, and the crust will firm up to that satisfying crunch. Serve immediately while the contrast between that crispy, golden crust and the tender, flaky interior is at its peak. Squeeze fresh lemon over top if desired—the acidity balances the richness of the fried coating beautifully.