Remove beef from the fridge, allow it to come to room temperature.
Cook egg noodles according to packet instructions, drain, refresh under cold water and set aside.
Place frozen vegetables in a large bowl, cover with boiling water, stand for 5 minutes and drain.
Heat a little oil in a wok. Add the beef and stir-fry.
Add vegetables to wok, stir-fry for two minutes, then add the stir-fry sauce. Add noodles to wok and toss, using tongs, until noodles are covered evenly in sauce and heated through. Stir through cashews.