Cut the lettuce leaves in half and cut them to the same size as the toast.
Place three pieces of toast next to each other and spread mayonnaise over each.
Lay 2 pieces of lettuce and 2 pieces of tomato on one of the pieces of toast and add some pepper.
Lay two pieces of bacon on the tomatoes (breaking the ends off if necessary so that they fit the bread). Lay two pieces of turkey breast on top and add pepper.
Repeat the process with the second piece of toast.
Carefully stack the second piece of the sandwich on top of the first (with the turkey breast facing upwards). Lay the final piece of toast, with the mayonnaise facing down on top and gently press the sandwich together.
Assemble each with two skewers through them to hold them together.
Prepare the other three sandwiches in the same way. Cut each sandwich diagonally with a large bread knife into two triangles. Each triangle should be held together with a skewer.