Peel and chop 3 small potatoes. Boil them in a pot with water and 1/2 tsp salt until soft.

Mix 1 tbsp soy sauce, 1 tbsp mirin, 1 tbsp water, and 1 tbsp sugar in a bowl to make the sauce.

Mash the boiled potatoes with a fork or potato masher while still warm.

Add 4 tbsp cornstarch and a pinch of salt to the mashed potatoes. Knead into a smooth dough.

Take about 1 tbsp of dough, flatten it, place 1/2 tbsp mozzarella cheese in the center, and shape into a round, flat disc.

Heat a pan with a small amount of cooking oil over low heat. Cook the potato discs until golden brown on both sides.