1 fatty mackerel
Salt, to cover
Vinegar, to cover
150g uncooked rice
2 tbsp rice vinegar
Sake, to taste
¾ tbsp sugar
Salt, to taste
Pickled ginger, for garnish
Rinse the mackerel with water, slit open along the back, cover with a generous amount of salt and let it stand for a day.
Cut the mackerel in half and remove all the bones.
Immerse the mackerel in vinegar with the skin side down for 10 minutes, turn it over and let it stand for 5 more minutes.
Place the mackerel on an inclined cutting (chopping) board to drain the vinegar (about 30 minutes).
Meanwhile, cook 150 g rice and allow it to stand for about 15 minutes.
To make seasoned rice vinegar, put the rice vinegar, sake, sugar, and salt into a pan and mix over low heat to dissolve all ingredients.
Put the rice into a wooden barrel, making a mountain shape. Pour the rice vingear over it and swiftly and thoroughly cut the vinegar into the rice with a rice paddle. Cover the rice with a wet cloth and let stand for 15 minutes. Change the cloth and let stand until the rice cools down.
Make bar shapes with the rice, the same shape as the mackerel pieces.
Rip the thin skin off the mackerel.
Place it onto a wet cloth with the skin side down and make a rectangular shape.
Place the pickled ginger and the sushi rice over the mackerel, wrap up with a wet cloth and shape the sushi with a bamboo-woven mat.
Cut it into slices and serve on a dish.