If the salmon contains any pin bones, remove them with tweezers.
Crack the peppercorns and coriander seeds. You can give them a very brief spin (just a second or two) in a spice grinder or simply place them onto the rimmed half sheet pan and use the back of a heavy skillet to crush them a bit.
Place cracked spices into a small mixing bowl. Line the rimmed half sheet pan with parchment paper.
To the mixing bowl, add the sugar, salt, and lemon zest. Use the tips of your fingers to gently rub the ingredients together and mix them up.
Place the salmon, skin side down, on the parchment-lined sheet pan. Brush evenly with the lemon juice.
Sprinkle the salt mixture over the salmon, covering completely. If your fillet has thicker and thinner sections, apply the mixture a little more heavily where the salmon is thicker and more lightly where the fillet thins out toward the tail.
Cover evenly with the dill.
Cover the salmon with another layer of parchment and then another sheet pan. Weight the top sheet pan with two 16-ounce cans.
Refrigerate for 48 hours if using thick fillets like the ones pictured. Start checking at the 24 hour mark for thinner cuts. Your preferred level of cure is somewhat of a personal matter, but a visible reduction in volume and plenty of liquid in the pan are good indications that the salmon is ready. The outside faces of the fillets may appear a little bit dense, but the salmon should be beautifully tender when you slice it.
Scrape the dill and curing mixture from the salmon. Rinse well and pat dry.
With a very sharp knife, slice very thinly on the bias to serve.