Process garlic, lemongrass and shallots in the food processor until finely chopped. Place the chicken in a large non-metallic bowl. Add all the marinade ingredients and mix using your hand until combined. Cover with plastic wrap and place in the refrigerator for 2 hours or overnight.
Heat oil in a wok or a large non-stick frying pan over medium-high heat. Fry the chicken pieces with the marinade and cook for 5-6 minutes or until browned.
Add the chillies and cook for 2 minutes, stirring occasionally. Add the coconut juice, stir and cover. Cook on high heat, stirring occasionally for 6-8 minutes until the juice is reduced by half. Add the spring onion. Garnish with coriander leaves. Serve with steamed jasmine rice.