1.Heat oil in wok; cook lemon grass, chilli, galangal and garlic, stirring, until fragrant. Add pork; cook, stirring, until cooked through. Add curry paste; cook, stirring, until fragrant.
2.Add beans, fish sauce, juice and sugar to wok; cook, stirring, about 5 minutes or until beans are just tender. Remove from heat.
3.Add onions, basil, coriander and half the peanuts to pork mixture; stir to combine.
4.Serve pork mixture in lettuce cups sprinkled with remaining peanuts.