Gravlax is a technique originally used for preserving fish (a tradition dating back to the Vikings). Today, it is a sophisticated appetizer that requires no cooking, only a long chilling time under slight pressure.
The ratio of salt to sugar (usually 1:1) is crucial for drawing moisture out of the salmon, which cures it and firms its texture. Dill lends the fish its characteristic, fresh flavour.
It is traditionally served with a creamy mustard-dill sauce known as Hovmästarsås.
In a bowl, mix the salt, sugar, crushed pepper, and half of the chopped dill. For a more authentic taste, you can add a pinch of juniper berries.
Rinse the salmon fillet, pat it dry, and use tweezers to remove any remaining pin bones. Make a few shallow cuts in the skin to help the marinade penetrate.
Line a baking dish with plastic wrap (leaving an overhang) and sprinkle half of the cure mixture on the bottom. Place the salmon skin-side down.
Sprinkle the remaining cure mixture over the salmon and press the remaining fresh dill on top. Wrap the salmon tightly with the plastic wrap.
Place a cutting board on top of the salmon and weight it down (e.g., with cans or heavy pots). Refrigerate for 48 hours.
Every 12 hours, flip the salmon and pour off any excess liquid that has formed.
In a small bowl, mix the mustard, sugar, and wine vinegar. Mix well.
Slowly whisk in the oil until the sauce thickens and emulsifies (similar to mayonnaise).
Finally, stir in the chopped dill and season with salt and pepper.
After 48 hours, remove the salmon from the plastic wrap. Gently wipe off (or scrape) the excess cure and dill. Do not rinse the fish with water.
Using a sharp, thin knife, slice the salmon on the bias into very thin slices, starting from the thick end. Cut almost to the skin, but leave the skin on the board.
Serve with Hovmästarsås, slices of rye bread, and optionally with lemon and fresh dill.