01 - Toast all 6 slices of sandwich bread until golden brown and crisp on the edges.
02 - Spread mayonnaise evenly over one side of each toasted bread slice using a butter knife or spatula.
03 - Place 2 slices of toast mayo-side up on a clean work surface. Layer each with half of the turkey or chicken, 1 slice of ham if using, 2 strips of bacon, sliced tomato, and a lettuce leaf. Season lightly with salt and pepper.
04 - Top each assembled layer with a second toasted bread slice, mayo-side facing up, to form the middle deck of the sandwich.
05 - Repeat the layering process on each middle bread slice with the remaining turkey or chicken, ham, bacon, tomato, and lettuce. Season again with salt and pepper to taste.
06 - Place the third toasted bread slice on top of each sandwich, mayo-side facing down, completing the triple-decker assembly.
07 - Insert 2 toothpicks into each sandwich to hold the layers together. Using a sharp knife, cut each sandwich diagonally into 4 triangular wedges.
08 - Plate the sandwich wedges immediately and serve with potato chips, a side salad, or your preferred accompaniment.