Whisky (something peaty and smoky is ideal, I used Jura)
Melba toast/crackers or crispbread
Rub the fillet with whisky
Make a mix of equal quantities of salt and light brown sugar (enough to generously coat both sides of the fillet) and add some lightly crushed dried rosemary.
On a large piece of aluminium foil in two layers, spread a layer of the cure, set the fillet on top, skin side down, then spread the rest of the mix over the top and dribble some more whisky over the top.
Wrap the fillet tightly in the foil and leave in the fridge at least over night, longer if the fillet is really thick. The one I had was just about 1cm so over night was plenty.
To serve, wash the cure off the fillet and pat dry, then slice finely at a very flat angle. A fish knife with a flexible blade is ideal for this. You can wrap the salmon in clingfilm and it’ll keep for a few days in the fridge.
Serve on melba toast, crackers or crispbread. Add a little light horseradish or mustard cream if you fancy it but with mine, that wasn’t necessary.