1. Break pak boong into 5cm pieces and place in a large bowl. Add garlic, chillies, oyster sauce, 1 tablespoon fish sauce and sugar to the same bowl.
2. Heat oil in a wok over high heat. When oil is smoking hot, add all ingredients and toss together. Add another tablespoon of fish sauce and stir-fry for 1-2 minutes or until just wilted. Serve with steamed rice.