Pork and Green Beans with Ginger Sauce

(from The Complete Stir-Fry Cookbook, p. 72)

¾ cup (185 ml/6 fl oz.) soy sauce (I recommend low-sodium soy sauce)
4 tablespoons white or rice wine vinegar
1 teaspoon sugar
pinch of dried chili flakes
3 teaspoons cornflour
600 g (1 ¼ lb) pork fillet, trimmed and cut into thin slices
2 tablespoons peanut oil
350 g (11 oz) green beans, cut into short lengths
2 cloves garlic, chopped
2 tablespoons grated fresh ginger

1.Place the soy sauce, vinegar, sugar, chili flakes, cornflour and 1/3 cup water in a bowl and mix well. Add the pork and toss to coat well.
2.Heat a wok over high heat, add half the oil and swirl to coat the side. Drain the pork (reserving the liquid for later) and add to the wok. Stir-fry over high heat for 1-2 minutes, or until brown. Remove the pork from the wok.
3.Heat the remaining oil, add the beans and stir-fry for 3-4 minutes. Add the garlic and ginger and stir-fry for 1 minute, or until fragrant. Return the pork and any juices to the pan and add the reserved marinade. Bring to a boil and cook, stirring, for 1-2 minutes, or until slightly thickened. Serve with steamed rice.