Heat 2 tablespoons of the oil in a hot wok until the surface seems to shimmer slightly.
Add chicken and stir-fry for 1 minute. Remove from wok and set aside.
Add remaining oil to hot wok with onion and ginger and stir-fry for 1 minute or until onion is lightly browned.
Toss in noodles, reserved chicken, shao hsing wine or sherry, sugar, tamari, vinegar and sesame oil and stir-fry for 1½ minutes.
Add bean sprouts and half the spring onions and chilli and stir-fry for a further 30 seconds or until chicken is cooked through and noodles are hot.
Arrange noodles in bowls, top with remaining spring onions and chilli and serve immediately.
