Cook noodles following packet directions. Drain well. Set aside.
Meanwhile, combine cornflour and soy sauce in a small jug. Add oyster sauce, shao hsing, stock cube and 3/4 cup water. Mix well to combine.
Heat a wok or large frying pan over high heat. Add oil. Swirl to coat. Add mince. Stir-fry, breaking up mince, for 3 to 5 minutes or until browned. Transfer to a heatproof bowl.
Add pak choy to wok. Stir-fry for 3 minutes or until leaves are starting to wilt. Transfer to a bowl. Add onion and celery to wok. Stir-fry for 3 to 4 minutes or until just starting to soften. Add garlic. Stir-fry for 30 seconds.
Return mince to wok. Add sauce mixture. Stir-fry for 1 minute or until sauce boils. Add carrot, bamboo shoots, snow peas and corn. Stir-fry for 1 to 2 minutes or until vegetables are just tender and sauce thickens. Add noodles. Toss to combine. Serve chow mein topped with pak choy, chilli and green onion.