Nope used to bake a boned mackerel in the oven, just as it was, rolled in flour. It would come out all crispy around the edges, oil from the fish in the baking tin. Used to love the taste, often got to the point where I couldn't eat anymore, probably too greasy but the flavour was great. Now they just seem to boil in water for some reason.
This is a joke, or should be, unfortunately its true. Bought this this morning, just to prove a point. This is supposed to be a Mackerel fillet from Morrisons. as you can see only 6 1/2 ins long, the fish with head could only have been 12 ins maximum. Its about time they stopped slaughtering undersized fish.
I've filleted quite a few mackerel (up to 200 at a time), and reckon the minimum length of fish (tip of snout to fork of tail) would have to of been around 10"/250mm to produce a 6.5" fillet.