1. Stir together mayonnaise, basil, parsley and thyme. Season with salt and pepper. Cover and refrigerate.
2. Making one sandwich at a time, spread some herb mayonnaise on 1 side of 3 slices of bread. Layer 2 slices of turkey and 2 slices of tomato on 1 piece of toast, and top with a second, mayonnaise side up. Add 2 slices of bacon and 1 lettuce leaf. Top with third piece of toast, mayo side down.
3. Lightly press sandwich down and cut in half diagonally. Secure with toothpicks. Repeat to make remaining sandwiches.