Toast the bread slices until golden brown.
Spread a thin layer of mayonnaise on one side of each slice.
Layer the ingredients in the following order: bread slice (mayonnaise side up), lettuce, turkey, bacon, tomato slices, cheese, cucumber slices, sliced boiled eggs, salt, and pepper.
Place another bread slice on top and repeat the layering process.
Finally, top with the third bread slice (mayonnaise side down).
Gently press the sandwich together and secure with toothpicks, inserting them in each corner.
Carefully slice the sandwich diagonally into quarters.
Serve immediately and enjoy!