1. Heat oil in a wok, to a very high temperature.
2. Add all the vegetables and stir fry on high heat for 2-3 mins.
3. Add the garlic, oyster sauce and salt to the mixture. Mix well.
4. Serve immediately.

Note: 1. Since this is cooked on high heat in a short span of time, the vegetables retain their crunchiness along with their nutritive value. 2. Hoi sin sauce is a traditional Chinese sauce made from soya beans, sesame oil, and spices