1.Heat oil in a wok or large, deep frying pan, cook garlic, ginger and chilli, stirring, over high heat, for 1 minute or until fragrant.
2.Add chicken to wok, cook, stirring, until browned. Add sauce, chestnuts, sprouts and onion, stir until heated through.
3.Spoon chicken mixture into lettuce leaves, sprinkle with nuts. If you like, serve with some extra chopped chilli and lemon wedges.
You will need about 2 iceberg lettuces for this recipe. To easily separate the lettuce leaves without tearing, use a sharp knife to remove the core at the base of the lettuce. Hold the lettuce, cut-side up, under cold running water. Gently separate leaves one at a time, using the weight of the running water between the leaves to assist you.