Combine the sauce ingredients in a bowl, stirring well to remove any lumps. Set aside.
Heat the oil in a wok over a high heat until the oil starts to shimmer. Add the ginger and garlic and stir-fry for a few seconds, then tip in the beef and continue stir-frying for 2–3 minutes until the meat is lightly browned.
Add the sauce ingredients, stir the mixture thoroughly and cook until reduced to a thick glaze. Tip the beef into a bowl with the remaining ingredients. Check the seasoning and serve as a warm salad.