In a bowl, mix the sugar, salt, dill and lemon zest.
Lay the salmon fillet into a deep dish (it will loose water and therefore you want to ensure that the fish is in a deep dish and can hold the resulting brine).
Sprinkle with the lemon juice and then pack tightly with the sugar-salt mixture.
Place in the refrigerator and let marinate for at least 36 hours.
Remove the fish from the brine and wash thoroughly. At this stage the cured salmon is ready for serving but can easily be wrapped in plastic foil and kept in the refrigerator for a up to 5 days.
Notes
There are some interesting flavors that can be added to the curing process. You must ensure however, that the 2:1 ratio of salt and sugar will not be altered.Vodka or Aquavit can be added to the brine - very “Nordic” chic; Szechuan pepper or fresh or pickled ginger or sake for Asian taste nuances; double the amount of dill, juniper berries and allspice for Scandinavian authenticity and more.