Canola or corn oil, for frying
1 pound redfish filets
1 cup coarse cornmeal
1/2 teaspoon kosher salt, plus more to taste
Freshly ground black pepper, to taste
1/2 cup mayonnaise
Sriracha, to taste
4 potato buns
2 tablespoons unsalted butter, room temperature
Sliced pickles, tomatoes, onions, and lettuce leaves, to finish
Pour oil to a depth of one inch into a medium cast iron skillet and place over medium to medium-high heat. Heat another skillet or griddle over medium to medium-low.
Pat the fish dry, score the skin, and sprinkle with salt. In a medium mixing bowl, toss the cornmeal with the salt and pepper. Mix the mayo and sriracha together in a small bowl and set aside. Line a cooling rack with paper towels.
Spread butter on the insides of the potato buns and place, cut side down, on griddle. When the oil is hot, press the filets on both sides into the cornmeal mixture. Slide the filets into the hot oil and fry filets for about 5 minutes. Remove fish to the paper towel-lined rack to drain. Sprinkle with salt.
To finish the sandwiches, pull the buns off the griddle and spread the spicy mayo over the cut sides. Place two pieces of fish on each bun and finish with toppings of your choice. Serve with cole slaw.