Bone and slice the roast duck. Shred the lettuce and arrange on a serving platter, with duck on top.
Drain the pineapple chunks and arrange over the duck. Pour the pineapple juice into a saucepan and heat slowly.
Blend the cornstarch and water to a paste, then stir in to thicken. Pour the sauce over duck and pineapple.
Refrigerate to chill before serving.Servings: 4