Mackerel skin

 

grilled mackerel

mackerel with transparent skin layer peeled off

Have been enjoying line caught fat mackerel for a few weeks, like to have them salted for a day or two and grilled, just find the skin a bit on the hard side. 

Finally remember have seen in sushi shop that chef peels off a thin transparent layer from mackerel before serving. Try to do so and actually not that difficult, start from the top cut end and peel towards the tail, and the filet won't curl up while drying. After grilling, the skin is soft and much easier to eat.