Mix chicken, ginger, salt, pepper and potato flour (if you have a mini food processor, why not using it?) and make some balls.

3/4 fill your bowl with water and transfer it to a saucepan. Repeat twice. (Measuring 3 bowls of water) Bring to boil and drop the chicken balls. Gently cook.

Just before serving, add sliced Chinese cabbage, soy sauce, mirin and some more pepper.

To thicken the soup, mix potato flour and water in a small bowl. Bring the soup to near boiling point and pour it in mixing well.