Remove any pin bones in the fish if necessary.
Chop the dill, zest the lemon and mix with the salt and sugar. Sprinkle a thin layer of the 'cure mix' on to a tray and place the mackerel fillets on top. Season the top of the fish with more cure mix so the fish is completely covered. Leave for 10 minutes to cure.
Wash off the cure mix thoroughly then pat dry with a clean cloth.
Thinly slice and enjoy on rye bread with crème fraiche.
«Careful not to over cure the fish or it will become too salty. »