Cut the fillet into thin strips and finely mince them. (A broad-bladed knife called a deba bocho is best suited for this task.)

Place the chopped sardines in a mortar and grind them until becoming a paste. Add the red miso, ginger juice, flour, and TREHA^®, and then continue to grind.

In a pot, pour 3 cups of water and a pinch of salt and bring it to a boil. With a spoon, form the fish paste into bite-size balls, gently drop them into the simmering water, and cook over low heat for 2 to 3 minutes.

Serve the fish balls in a dashi broth or add to hot pot (nabe) dishes.