01 - Toast all 6 bread slices until golden brown and slightly crisp on the edges.
02 - Spread mayonnaise evenly over one side of each toasted bread slice.
03 - Place 2 toast slices mayo-side up on a clean work surface. Layer each with half the turkey or chicken, 1 slice of ham if using, 2 strips of bacon, tomato slices, and a lettuce leaf. Season lightly with salt and pepper.
04 - Top each stack with a second toast slice mayo-side up. Repeat layering with the remaining turkey or chicken, ham, bacon, tomato slices, and lettuce. Season again with salt and pepper.
05 - Place the third toast slice mayo-side down on top of each stacked sandwich to complete the triple-decker assembly.
06 - Insert 2 toothpicks into each sandwich to hold the layers together. Using a sharp knife, cut each sandwich diagonally into 4 triangular wedges.
07 - Arrange the wedge sections on plates and serve immediately with potato chips or a side salad alongside.