Whisk together egg and buttermilk in a medium bowl. Combine cornmeal, salt, and pepper in a shallow dish. Dip tomato slices in egg mixture, then coat with seasoned cornmeal.
Heat oil in a large sauté pan over medium heat. Place tomato slices in pan in a single layer, and cook until golden brown on bottom, about 3 minutes. Flip and brown other side, about 3 minutes more. Interior should be cooked through but not mushy.
Place 2 tomato slices on each of 4 serving plates and top each slice with 3 shrimp. Spoon 1 1/2 tablespoons Remoulade Sauce over each slice, and garnish, if desired. Serve immediately.