Fish can be scary. All those scales, the smell, the shiny dead eyes watching you while you pick at the bones – it’s easy to see why most people prefer it battered.
But in the interests of culinary discovery and, well, nosiness (because how do mackerel fillets go from swimming about happily, to being vacuum packed and put in the supermarket chiller?) I took a River Cottage session on filleting and cooking seafood, and for novices, mackerel is apparently the fish to start with.
And so, we excavate two fillets from a plump, iridescent, caught-that-morning fish…
You start by slicing along the belly – starting from between the two tiny little fins near the head, cut towards the tail. You can then hook your index finger in and pull out the guts – search for a fine membrane, towards the head, and break it with your finger (it gives a satisfying twang). You don’t need much pressure, then chuck the sack of guts in the bin. It shouldn’t be too bloody, but if it is, now’s the time to give the fish a wash.
Next, hold the head firmly in one hand, tail pointing away from you. Cut down into the ‘armpit’ (or ‘fin pit’) of the fish, just on the tail side of its pectoral fin, until you touch the spine. Then turn the blade until it lies flat on the spine, parallel to the chopping board, sharp edge pointing tailwards, and slice along the length of the fish until the fillet is separated from the body. Flip and repeat, like this:
Cut away the belly bones (the dark membrane that contains a rack of very fine bones):
Then remove the pin bones, which run down the centre of the fillets, by slicing (being careful not to cut through the skin on the other side) a v-shaped groove:
And then, scrappy edges aside, ta-dah, you end up with these – and feeling very proud of yourself, too: