Zest the lemon and chop the herbs.
Place lemon zest, peppercorns and Erythritol into a spice grinder or mortar and pestle and grind until fine.
Mix with rock salt and spirit to form a rough paste.
Lay cling wrap out on bench and spread a third of the cure over the centre of it.
Place half of the chopped dill on top of the salt cure.
Place the salmon on top of the cure and spread the remaining dill over and around the fillet.
Cover with the balance of the salt cure.
You want the dill to be the closest ingredient to the salmon.
Wrap cling wrap very tightly around fish and cure and add a few more cling wrap layers.
Place in a container and sit a plate on top, weighted with tin cans.
Sit in the refrigerator for 48 hours, turning every 12 hours or so.
The salmon will be cured when it is firm to the touch.
Wipe salt cure off.
Gently run a sharp knife under the skin to remove.
Slice salmon thinly.
Salmon gravlax will keep for 3 to 5 days in the refrigerator.