Preheat the oven to 200°C.
Pierce the duck skin with a knife, season with salt and Sichuan pepper, and place on a wire rack in a roasting tin.
Roast the duck for 25 minutes.
Reduce oven temperature to 120°C and cook for 75 minutes, basting with reserved duck fat every 20 minutes.
Boil stock with thyme, butter, and lemon rind, then braise lettuce in the mixture for 10 minutes.
Increase oven to 180°C, glaze the duck with honey, and roast for 20 minutes while basting.
Drizzle soy sauce over the duck during the final baste and let it rest once cooked.
Mix mashed potato, flour, baking powder, eggs, and milk to create a pancake batter.
Fry spoonfuls of batter in oil until golden-brown on both sides.
Carve the duck and serve with lettuce, pancakes, and a spoonful of cooking liquor.