Method:

1. Combine soy sauce, sesame oil, seeds, rind and beef in a large bowl. Refrigerate, covered, for 20 minutes.
2. Heat oil in a large wok until smoking. Cook beef, in batches, for 2 minutes or until browned. Remove from wok and set aside.
3. Add garlic, and cook for 20 seconds. Add Choy sum, broccolini and stock and cook for 2-3 minutes until broccolini is tender.
4. Return beef to wok and cook a further 2 minutes.
5. Remove wok from heat and quickly toss through the noodles. Serve with chopped fresh chilli if desired.