1 kg boneless beef topside
1/2 cup soy sauce
3 tbsps cornflour
300 ml beef stock (better if condensed)
2 tbsps sugar
2 tbsps vegetable oil
4 cups sliced shiitake mushrooms
1 head Chinese cabbage (bok choy), thinly sliced
2 medium red peppers, cut into 5cm long strips
3 stalks celery, sliced
2 medium green onions, cut into 5 cm pieces
Hot cooked regular long-grain white rice