Sprinkle fish with Cajun spice and salt, then cut each fillet in half lengthwise. Whisk egg white and water in a shallow dish. Place cornmeal in another shallow dish. Dip the fish in the egg mixture, then in the cornmeal. (Discard any leftover egg and cornmeal.)Advertisement
Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Add the fish (it will be a tight fit) and cook until golden brown on the bottom, 3 to 5 minutes. Turn over, swirl in the remaining 1 tablespoon oil and cook until the fish is golden brown on the other side and opaque in the middle, 3 to 5 minutes more.
Combine mayonnaise and pickle in a small bowl. To assemble the sandwiches, spread 1 generous tablespoon of the mixture on each bun. Top with a piece of fish, tomato, onion and lettuce.
2 starch, 1 1/2 vegetable, 2 1/2 lean meat, 2 fat