Cook noodles in a large saucepan of boiling water, following packet instructions, until tender. Drain.
Meanwhile, heat half a tablespoon of oil in a wok over high heat. Stir-fry chicken, in batches, until browned.
Heat remaining half tablespoon oil in wok; stir-fry onion and capsicum for 2 minutes. Add garlic, ginger and snow peas; stir-fry for 2 minutes.
Add choy sum, sauces, lime juice, chilli paste and chicken. Stir-fry for 2-3 minutes or until chicken is cooked through. Add noodles and toss until hot. Serve.