||Cut the beef across the grain into thin strips. Rub the brown sugar into the beef strips, then add a little of the oil to the beef. Mix well. Rinse the rice noodles under hot water, gently separate. Pan-fry or steam the noodles until hot, drizzle with sesame oil. Set aside.
||Heat the wok, ensure it is hot. Stir-fry the beef strips in 3 batches, reserving each cooked batch to rest in a warm bowl. Reheat wok between each batch.
||Reheat the wok, add remaining oil and heat. Add the bok choy, and stir-fry for 2 minutes. Add the combined oyster and soy sauces, stir-fry to mix.
||Return the beef to the wok, toss to combine. Place rice noodles on serving plate, add beef stir-fry. Sprinkle with sesame seeds and sliced red chilli if desired.
||Serving suggestion: Serve with shredded ginger and spring onions.