In a bowl, add the chicken mince, chicken fat, and salt. Mix thoroughly until the chicken mince becomes sticky.
Add all of the remaining ingredients except 1 tablespoon of sake. Mix well.
While mixing, gradually add the remaining sake to the bowl. The mixture should be soft but not too soft. Do not add all of the sake if the mixture becomes too soft to grab by hand and form a ball.
Boil some water in a pot and coat a cutlery spoon with a little bit of oil.
Grab chicken mince with one hand (the Ieft hand if you’re right-handed, or the right hand if you’re left-handed) and squeeze out mince between the thumb and the index finger. The mince should come out forming a round shape.
Take the formed meatball with the spoon and drop it into the pot with boiling water. Repeat this for the rest of the mince.
Boil the meatballs for 5 - 7 minutes until cooked through. The cooking time depends on the size of the meatballs. When the meatball floats and feels light when you pick it up, it’s ready.
Take the meatballs out and set them aside. Cook the meatballs in small batches so that the surface of the boiling water has no more than one layer of meatballs floating.