Put the steak in a bowl, add the chilli flakes, season and toss to combine. Set aside.
Cook the noodles according to pack instructions, then drain and set aside.
Heat the oil in a large wok or frying pan and stir-fry the ginger over a high heat for 30 seconds. Add the beans and stir-fry 3-5 minutes, then remove and set aside.
Increase the heat to high and stir-fry the beef in batches for 1-2 minutes.
Return the beans to the wok along with the noodles and teriyaki sauce. Toss to combine and stir-fry 1-2 minutes until hot.