||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.
||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 snow peas and bok choy, and stir-fry for 2-3 minutes. Add the combined oyster and soy sauces, stir-fry to mix.
||Return the beef to the wok, toss to combine. Transfer to serving plate, sprinkle with bean sprouts.
||Serving suggestion: Serve with rice.