Fill a Dutch oven or a cast iron pot with 3-inches of canola oil pot. Heat oil to 375 degrees F. Place a wire rack over a baking sheet and set aside.
Grab 2 shallow bowls and set up the dredging station. Whisk the buttermilk and pickle juice in the first bowl. Then, combine the cornmeal, flour, cornstarch, creole seasoning, onion powder, pepper, salt, and cayenne pepper in the second bowl.
Pat the catfish fillets dry with a paper towel. Dip the fish in the buttermilk until submerged and then coat in the cornmeal mixture being sure to cover both sides. Gently press the breading into the fish to help it hold.
Carefully place the fillets into the hot oil for 7 minutes, turning halfway through. Be careful not to crowd the pot, it is best to only fry 1 or 2 fillets at a time. Remove the fillets and place them onto the prepared baking sheet to allow excess oil to drip off. To keep the catfish hot as you cook the remaining fillets, place the baking sheet into the oven on the WARM setting.
Make the remoulade by adding all ingredients into a food processor or blender. Puree for 15 seconds and then pour into a small bowl or ramekin for serving.
Squeeze a lemon wedge over the fillets and garnish with some chopped parsley. Serve warm with spicy remoulade for dipping.
Notes
If you don't have buttermilk on hand, you can substitute sour milk. Mix 1 cup of milk with 1 tablespoon of lemon juice or white vinegar and stir. Let it sit for 5 minutes before using.
If you want your remoulade less spicy, start with 1 teaspoon horseradish and 1 teaspoon hot sauce. Mix and then add more to your taste.
This remoulade sauce recipe makes 8 ounces and will keep for up to 1 week in an airtight container in the fridge.
Nutrition includes 1 fried catfish filet and 1/4 cup remoulade.