Mix the sauce ingredients in a small jug or bowl and set aside.
Place the chicken in a bowl and mix with 1 tablespoon of the sauce. Set aside while you prepare the rest of the ingredients.
Place a wok or large frying pan on a medium to high heat and add the oil. Add the chicken when the oil is hot and cook for a few minutes until it is brown on the outside.
Add the mushrooms, cabbage and the whites of the spring onions/scallions and cook for a few minutes until the mushrooms are brown and the cabbage has softened.
Add the garlic, bean sprouts and the green parts of the spring onions/scallions and cook for a minute or two until fragrant.
Add the noodles and toss for a minute or so until hot.
Pour on the sauce, toss the noodles, chicken and veggies for 30 seconds until incorporated, remove the pan from the heat and serve immediately topped with more spring onions/scallions as desired.