I started with a recipe from Tyler Florence and added/changed/deleted some ingredients and here is the result.
2 T. unsalted butter1 large garlic clove, smashed
2 long soft-crusted French bread baguettes
6 (6-ounce) catfish fillets
Sea salt and freshly ground black pepper
Creole Seasoning (to taste)
1 cup milk
1 cup white corn meal
Thinly sliced tomatoes
Pour about 3 inches of oil in a deep fryer or large, heavy cast iron skillet and heat to 375 degrees F. Preheat the oven to 250 degrees F.
Melt the butter in a small saucepan over medium-low heat. Add the smashed garlic and swirl the pot around to infuse the garlic flavor into the butter. Slice the French bread in 1/2 lengthwise and brush the top and insides with the garlic butter. Stick the bread in the oven for 5 minutes to warm it through.
Lightly season both sides of the catfish fillets with a salt and pepper and the Creole/Cajun seasoning. In a wide bowl, pour the milk. Whisk together the cornmeal, salt and pepper and seasoning in a pie dish. Dip the catfish in the wet batter, then dredge in the dry; being sure to cover the fillets completely. Gently drop the fish in the hot oil in batches so the pan is not overcrowded. Fry the fillets for 3 minutes and then drain on a platter lined with paper towels; sprinkle with salt while they are still hot.
To assemble the sandwich, put the pickles, lettuce and tomatoes across the bottom 1/2 of the bread, lay the fried catfish on top. Add mayo/mustard if desired and close up the sandwich with the top 1/2 of the bread. Cut into portions and serve immediately with hot sauce and lemon on the side.