Location: Newport Beach
|you dont cook them in vinegar, you marinate / soak them. this goes for the pacific blue and green mackerel (saba), not the spanish (aji). the acetic acid in the vinegar cures the meat, just like citric acid is used to make ceviche.
3 parts rice vinegar
1 parts sugar
1 part pickled ginger
1 part lemon / orange / yuzu (quartered)
wrap the filets (deboned), skin on with dashi-konbu (flavored kelp), meat side down. soak for 45 minutes to 2 hours depending on outside air temperature. store in refrigeration until marination is complete. drain the juice, and unwrap the fish. slice and serve.
note: it is difficult to remove the bones without destroying the whole form of the meat if you attempt to debone the fish after marination. the acetic acid (vinegar) weakens the bones so they break off when you pull.
the reason that you marinate the blues and greens is that the fish taste is very potent. sushi chefs often refer to mackerel as the "fishy fish". it is often served with pickled or fresh grated ginger, and lemon to make it easier on the palette.
in case if you havent noticed, the parasites are in the stomachs of the fish, which are removed before serving. also, traditional sashimi (raw fish, not cooked)is not served with rice. sushi (nigiri) is raw fish served over rice is a fairly new concept, which came only after the discovery of electricity. btw, id be scared to eat it as well, knowing that you were the one preparing it.