Mackerel with turnip greens and hazelnuts

To prepare mackerel with turnip greens and hazelnuts, start by cleaning the mackerel. Cut a slit in the stomach 1, gut the fish and then rinse under running water 2. Cut a slit along the top, place the knife under the fin and cut towards the tail 3.

Avoid sawing when cutting into fillets 4 5, remove the underside and lastly, trim the edges to give the fillets a regular shape 6.

Debone the fish using the special tweezers 7. Place half of the sugar in a baking tray to form a roughly 0.2 inch thick layer, then place the 4 fillets on it, skin side down 8. Cover with the remaining sugar 9.

Leave to marinade for 20 minutes at room temperature. Once this time is up, remove the mackerel from the marinade 11 and rinse under running water 12.

Fill a bowl with cold water and dissolve 2 tablespoons of salt 13 in it, add the fillets 14 and leave them to soak for 2-3 minutes. This water and salt solution creates an enriching sea brine effect and adds a savory touch. Place the fillets on some absorbent paper 15.

Clean the greens by removing the toughest parts 16. Boil the greens in water, salt and a pinch of bicarbonate for 2 minutes 17. Drain and place them in a bowl with cold water and ice to stop the cooking process 18.

Dry the greens on a tray lined with absorbent kitchen paper 19. Place the hazelnuts on a tray lined with parchment paper 20 and toast them in a static oven preheated to 355° for 8-10 minutes 21.

Blend the hazelnuts in the mixer while sill hot 22. Once sandy in consistency, add the water 23 and a pinch of salt. Continue blending into a sauce 24.

Sieve the sauce 25 so that it is smooth 26. Cook the mackerel: heat a drizzle of oil in a pan, add the fillets skin side down 27 and gently press down so that they do not curl up.

Brown until the skin is golden, then turn them over and cook for a few seconds on the other side 28. When ready, place them on a tray with some absorbent paper; dab the apple cider vinegar over the mackerel skin while still hot 29 and season with the maldon salt 30. This will help them absorb the flavors better.

Now turn to the greens: heat a drizzle of oil in the same pan you cooked the mackerel in 31. Add the greens 32 and thoroughly brown them on both sides 32, then a spoon of lemon juice, simmer and reduce 33.

Place the greens on the absorbent paper too and season with a pinch of salt 34. Serve the fillets with the hazelnut sauce 35 and the turnip greens 36.