Gently pull the skin off of the chicken breasts. Place on a baking tray and pop in the oven at 180C/356F for 15-20mins, or until crispy. Timings will depend on how big the skin is and how much it was cooked beforehand, so just be vigilant. Also depending on how well the skin was originally seasoned you might want to season with salt & pepper beforehand too. When done allow to cool for 5mins, this will help it crisp up even more.

Meanwhile, dice the chicken breasts into small cubes. Combine in a mixing bowl with mayonnaise and generous amounts of cracked black pepper. Taste a cube and adjust mayo/pepper to preference.

Butter one side of each slice of bread. Top two slices with lettuce, then spoon over chicken mayo. Crush the chicken skin with your hands or a knife and sprinkle over the chicken mayo. Top with second slice of buttered bread. Slice in half and enjoy!