Shrimp Po'Boy

Name: Shrimp Po'Boy
Cuisine: Cajun And Creole, Southern
Ingredients: 2½ teaspoons kosher salt; 1 teaspoon cayenne pepper; 1 teaspoon garlic powder; 1 teaspoon paprika; ½ teaspoon dried oregano; ½ teaspoon dried thyme; ½ teaspoon freshly ground black pepper; ½ teaspoon onion powder; Vegetable oil for frying; 1½ pounds medium shrimp (about 36), peeled, deveined; 1 cup buttermilk; 1½ cups all-purpose flour; 1 cup cornmeal; 4 8" French rolls, split horizontally; Rémoulade (click for recipe) or mayonnaise; Shredded iceberg lettuce, sliced tomatoes, dill pickles, hot pepper sauce (optional), preferably Crystal