How to Make It
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.
Spread 1 tablespoon mayonnaise over each of 2 bread slices. Top each slice with 2 lettuce leaves, 3 tomato slices, and 2 bacon slices. Top with remaining 2 bread slices. Serve immediately.