Shime Saba (Vinegar-Cured Mackerel)
Salt first, vinegar second: the salt draws water out of the mackerel and firms it, and a short soak in rice vinegar with kombu turns the surface white while the center stays pink and rich. That pink center is how shime saba should look, which also means the fish is essentially raw. Vinegar and salt do not kill anisakis, so the recipe only works with fillets sold for raw eating with a parasite-control freezing history. Kept at 4°C or below from thawing to serving, it is eaten the day it is made, with perilla leaves and shredded ginger on the side.