In a large skillet, melt the butter over medium heat. Add the onions, celery, bell pepper, salt, and cayenne. Cook, stirring, until soft for about 6 minutes. Add the shrimp and cook, stirring, for 3 minutes. Transfer the mixture to a large mixing bowl and let cool slightly. Add the garlic, green onions, 2 of the eggs, and 1 cup of the bread crumbs. Stir to mix well. Divide into 8 equal portions and form into patties. Put the flour in a shallow bowl and season with 1 teaspoon of the Creole seasoning. Put the remaining 1 cup bread crumbs in another shallow bowl and season with the remaining 1 teaspoon Creole seasoning. Put the beaten egg in yet another shallow bowl, add the water, and beat lightly. Heat the vegetable oil in 2 large skillets over medium heat. Dredge each patty first in the flour, then in the egg mixture, then in the bread crumbs, turning to coat completely and shaking off any excess. Cook 4 patties at a time in each skillet, until lightly browned, 5 to 6 minutes on each side. Drain on paper towels. To serve, spread both sides of each toasted bun with some of the tartar sauce, place a patty on the bottom half of the bun, dress with lettuce and tomatoes, and top with the other bun half.
Combine all ingredients thoroughly.
Recipe courtesy of Emeril Lagasse, Emeril's Food of Love Productions 2008