River Cottage'S Gravad Max (Mackerel Gravlax)

1. 1

   The quickest way to prepare the mackerel is to take the fillet from either side of an ungutted fish, bait-cutter style - i.e., slicing from head to tail as close as possible to the backbone. Wipe any blood or guts from the board you are working on as you go. The whole frames (i.e., skeletons with heads and tails still on and guts attached) from which the fillets have been taken can be kept and frozen, then used later for pot bait.

2. 2

   Mix together all the ingredients for the cure. Sprinkle some cure lightly over the bottom of your chosen tray, box, or dish, then place the first layer of fillets on it skin side down, with the thin edges just overlapping. Then sprinkle another, slightly thicker layer of cure over. Arrange the next layer of mackerel skin side up and sprinkle over another layer of cure, then place the next layer skin side down (as shown, above left). Keep going until you've used all your fish, or filled the dish.

3. 3

   Put the board/lid/plate on top of the final layer and weight it down with a brick, storage jar, or whatever comes to hand. Place in the fridge. You can eat the gravad max after 24 hours, but 48 is best. For really big fillets, you could wait for 72 hours. Remove the board and lift out the fillets carefully, one at a time. Give them a very quick rinse and then pat dry immediately with a clean cloth or paper towels.

4. 4

   You could serve whole fillets, leaving the problem of cutting it away from the skin and avoiding the pinbones (which are still there, running down the middle of each fillet) to your guests. Or, you could be kinder and trim the fish before serving. So, place the cured fillet on a board, skin side down, and run a flexible filleting knife between the flesh and the skin. Alternatively, you can sometimes just start the process with the knife, then peel the skin off with your fingers.

5. 5

   Now slice the skinless fillet off either side of the pinbone line to give you 2 long fillets - and a very thin waste piece in the middle with the pinbones in it, which you should discard. The belly-side fillet may require a final trim to remove the fine belly bones.

6. 6

   mix the mustard, sugar, and vinegar together. Add the dill, mix well, and leave to macerate for a few minutes. Mix again, then stir in the creme fraiche. Serve the mackerel - 2 whole fillets or 4 trimmed pieces per person - with the creamy sauce on the side and plenty of brown bread and butter.

* Per serving · 4 servings · Values may vary.