Rinse pork ribs thoroughly. Marinade with (A) for at least an hour. *The corn flour will ensure the meat comes out tender. Break up the sour plum into pieces & remove seed. Add to marinated pork. Prepare steamer & steam pork for 15-20 mins. Ensure pork is completely cooked before serving. The juicy meat with the tangy sauce goes really well with a bowl of fragrant rice.