In a wok, heat oil, add garlic and
chilies and cook, stirring occasionally, until garlic becomes
golden. Stir in pork and stir fry for about
2 minutes until almost cooked through. Add water chestnuts, heat for 2
minutes, then stir in fish sauce, 4 tablespoons water and add plenty
of black pepper. Stir in coriander and spring
onions. Serve garnished with spring onion
brushes.