For us, pickled mackerel (or salted mackerel) is indispensable in the cold season and especially during the winter holidays. It's wonderful served simply as an appetizer, with olives and some onion slices beside. If you also added some potatoes baked in the oven, it would be pure madness... I showed you last year a good method to pickle mackerel in brine and now I discovered another quick and easy way to pickle fish.
It's good to serve within 2 days and I recommend freezing the remainings. Then, you can thaw it whenever you feel like and, because the whole procedure of cleaning the fish is done only once, you can make strategic stocks. Also, the fish marinated in brine by the method in the link above can be frozen too, so you can choose any recipe you like.
Pick some mackerel which is as big and as oily as possible, without any brown spots, torn skin or smell. I buy it from the local fish shop, it comes frozen in individual pieces and you can see exactly what you are buying. In the supermarket, it comes in bags, and to be honest, of dubious quality, small and fishy.
The quantities below are for 1 fish. I recommend testing first with one fish and then make a more serious batch of about 5 fish.