Remove any pin-bones from the salmon fillets.
Mix the salt, muscovado sugar, and granulated sugar in a large bowl.
Grind the seeds and pepper to a powder using a pestle and mortar.
Stir the ground seeds, lime zest, gin, and chopped dill into the sugar mixture.
Place one salmon fillet skin-side down on a large piece of aluminium foil.
Spread the salt mixture over the fillet and top with the second fillet skin-side up.
Wrap tightly in foil and pierce small holes to allow liquid to drain.
Sandwich the fish between two baking trays and weigh down with heavy weights.
Chill in the fridge for 2 to 3 days, turning the package periodically.
Scrape off the salt, slice very thinly on the diagonal, and serve.