Mix together the salt, sugar, pepper, lemon zest, juniper and dill to form a thick paste in a food processor
Cut the side of salmon in half lengthways so that you have two pieces of similar size.
Wipe the fish dry with kitchen paper and run your fingers over the flesh to detect any bones. Pull out any stray bones with tweezers.
Lay out kitchen film but leave attached to the roll.
Place a piece of fish on the cling film then spread the cure over the first piece. Drizzle with gin then add the other piece of fish.
Wrap tightly in the kitchen film then place in a resealable plastic bag.
Place on a dish then lay another similar dish on top in the fridge. Place a wight on the top plate.
Leave the fish for 72 hours, turning it over every 12 hours.
When the fish is ready carefully unwrap from the film. Use kitchen towel to wipe off any excess liquid.
To serve you can carefully peel off the skin. If you pull the skin back flat against the fish it should peel off in one piece without dragging the flesh.
Slice the salmon gravalax downwards in slices.
Alternatively, wipe off the cure with kitchen paper and use a filleting knife and take thin slices from the top of the fillet.