In a shallow dish, mix together the coconut milk, fish sauce, minced garlic, fresh coriander, turmeric, curry powder and pepper. Add chicken, and turn to coat. Cover, and refrigerate for 4 hours or overnight.
Preheat the barbecue for high heat.
To make the dipping sauce:In a saucepan, combine vinegar, water, sugar, 1 teaspoon minced garlic, minced chilli and salt; bring to the boil. Reduce heat to low, and simmer until liquid is reduced, about 5 minutes. Stir sauce from time to time. Remove from heat and allow to cool before use.
Place chicken pieces on soaked wooden or metal skewers. Discard remaining marinade, and place chicken on the barbecue. Cook for 10 minutes per side, or until slightly charred and juices run clear. Brush with dipping sauce before serving. Serve remaining sauce on the side for dipping.