1.To make larb dressing, combine cucumber, juice, oil, fish sauce and sugar in a glass bowl.
2.Heat peanut oil in a wok on high, swirling to coat. Stir-fry pork mince, in batches, for 2-3 minutes, until cooked through. Return all pork to wok Add fish sauce, kecap manic, garlic, ginger, onion and chilli, and stir-fry for 1-2 mins, until heated through. Remove from heat.
3.Add beansprouts and coriander and toss.
4.Place lettuce cups on a serving platter. Fill wit pork mixture. Spoon over a little larb dressing. Serve with lime wedges and remaining dressing.