Combine the sauce ingredients in a small bowl, stirring until the sugar and cornstarch are dissolved. Set aside.Heat the wok over high heat and add the oil. Once very hot, working quickly add the beef and fry, searing all sides, for 1-2 minutes. Add the carrots, garlic and ginger and fry for another minute or two. Add the remaining vegetables and fry for another two minutes. Do not over-cook, you want the vegetables to retain some "crunch." Stir in the sauce and simmer for a minute until thickened and then remove from heat.Serve immediately with steamed rice.