Slice the roll open and butter the inside. Toast cut-side down on a flat griddle. Meanwhile, coat the fish fillet in 1/2 cup of the cornmeal dredge, and then deep-fry until cooked through, 3 to 4 minutes.
Layer shredded lettuce and tomatoes onto the bottom of the roll, and top with the fried fish. Slather with 3 tablespoons of the remoulade then CHOW DOWN! Use the remaining dredge and remoulade for more fish or other recipes.