1In a measuring cup, mix one cup of good quality soy sauce, one cup of reverse fermented water, half a cup of Japanese sake and one fourth of a cup of mirin.
2Crush two garlic cloves and one piece of ginger using a kitchen hammer.
3Add the crushed garlic and ginger to the mixture.
4Add two pieces of fresh green scallion.
5Add two pieces of star anise; use a kitchen torch to slightly burn them.
6Pour the mixture into a saucepan and bring to a boil.
7Once boiling, turn off the heat and let it cool to room temperature.