The chopped bones are cleaned and cleaned. Yam and burdock are peeled and cut into pieces.
Put enough water in the soup. Put the ginger slices and the bones that fly under the water, and the burdock blocks. Put 1 teaspoon of vinegar. The role of vinegar is to promote calcium release from the barrel. After the fire is boiled, turn to low heat for 1 hour and then yam and red dates. Turn off the heat for another hour. Seasoning with salt can be done~