Pat duck legs dry, prick all over skin with a fork and rub with salt and pepper
Roast for 60-75 minutes on a wire rack then remove, drain fat and leave to sit for 10 mins under foil
Mix together all the sauce ingredients with 100ml water and simmer with the lid on for 8 mins (remove lid and reduce if not thick enough after 8 mins)
Shred the duck using 2 forks and add to a lettuce leaf with the cucumber, spring onion, chilli and coriander, a squeeze of lime juice and dollop of tamarind sauce