If you can find fresh mackerel, fillet it and cut the fillets into 4cm pieces then simmer in Miso, Mirin or Sake and a little sugar with a little water to cover the fish. The amount of Miso and Mirin and sugar for one medium sized Mackerel is about 2 ~ 3 tbsp each to suit your taste buds : )You can prepare Miso sauce in advance in a saucepan. Put all the ingredients together and heat it up! It’s a classic recipe and sweet Miso and ginger go very well with Mackerel.
Don’t forget to pour boiling water over the fish pieces before cooking in Miso sauce! It will get rid of the fishiness.