Method

If you have a zester, use it to remove the zest from the oranges and lemons or, alternatively, finely grate the zest. Mix half the zests with the sugar and salt, keeping the rest for garnishing.

Use tweezers to remove any pin-bones from the salmon fillet. Spread the zest-sugar-salt mixture evenly over the entire surface of the salmon, then cover it in plastic wrap and leave in the refrigerator for 3 days. After 3 days, remove the salmon from the refrigerator and wipe the marinade off the fish using paper towels. Wrap the salmon in fresh plastic wrap and freeze it for 12 hours.

Remove the salmon from the freezer and defrost. Place it on a board and cut it into thin slices using a very sharp knife. The traditional cutting technique begins diagonally at one corner of the salmon and then works back towards the centre of the fillet. Garnish the salmon with the remaining orange and lemon zest. Serve with hot, crusty ciabatta and a fresh green salad.