Trim about 2 inches from kangkong stalks and discard. Cut into 3 inch lengths, separating the sturdier stalks from the leaves. Wash thoroughly and drain well.

Take a wok and put heat oil on high. Add onions and garlic and cook for 2 minutes

Add pork and cook stirring regularly until lightly browned. About 5 minutes

Add vinegar and bring to boil. Continue cooking for 2 minutes then add soy sauce and water and bring to boil

Lower heat, cover and cook for 10 minutes or until pork is tender and sauce is reduced. Season with salt and pepper

Increase heat to high and add kangkong stalks and cook for 2 minutes stirring regularly

Add kangkong leaves and cook for another 2 minutes or until wilted and covered with sauce