Method

1. Preheat a griddle pan or non-stick frying pan. Place the chicken on a board and carefully cut through the breast horizontally to make two thin flat fillets. Drizzle a little oil onto each fillet and season with black pepper.
2. Cook on the hot griddle for a few minutes on each side, ensuring that the meat is completely cooked throughout. Transfer to a plate, sprinkle with half the herbs and set aside.
3. Meanwhile, mix the mayonnaise with half the herbs
4. Spread a little mayonnaise onto the base of each thin, then divide the lettuce and cucumber between them. Top with a piece of herby chicken and place on the lids before serving warm.