Step 1: Heat oil in wok, on a high temp. Add the chicken, stir fry for around 3mins, then add the onion.
Step 2: when the onion has turned golden, add a splash of soy sauce, along with the mushrooms and spring onions.
Step 3: stir-fry for around 4 mins, till the vegetables have softened, then add the bean sprouts, and another splash of soy sauce.
Step 4: cook for around 2mins, before adding the egg noodles (followed by another 2mins of frying).
Step 5: garnish as necessary whilst serving.