Crush peppercorns with the side of a knife (or roughly grind using mortar and pestle).
Combine peppercorns with salt, sugar and dill.
Place 2 large pieces of cling wrap on a work surface, slightly overlapping. Spread half the salt mixture in the shape of the salmon.
Place salmon on salt, skin side down. Top with remaining salt mixture.
Wrap with cling wrap. Place in a large dish. Top with something flat (like small cutting board) then 3 x 400g / 14oz cans ("Weights").
Refrigerate for 12 hours. There will be liquid in the dish. Turn salmon over (will be gloopy/wet)), then replace Weights and return to fridge. After another 12 hours, turn salmon over again, replace Weights. After another 12 hours, remove salmon from fridge. 36 hours total for Medium Cure - Perfect Gravlax to my taste (See Note 2 for description and more curing times).
Unwrap salmon, scrape off salt then rinse. Pat dry. If time permits, return to the fridge for 3 - 12 hours uncovered (dries surface better, lets salt "settle" and permeate through flesh more evenly).
Sprinkle over the 1/4 cup extra dill - for garnish and flavour.
Slice thinly on an angle, do not cut through skin (i.e. don't eat skin). Serve with toasted bread, Mustard Sauce, extra dill and lemon wedges.
Mix ingredients, making sure to season with salt and pepper. It should taste like a creamy mustard - a touch of tartness, but mostly to add moisture to the dish. You can add lemon juice and/or zest if you wish - I like to serve with wedges so people can adjust to their taste.