Rinse and pat dry salmon fillet. Remove any pin bones with dedicated, clean needle nose pliers.
Combine sugar, salt, and seasonings in a bowl until thoroughly combined.
Lay out two layers of plastic wrap, slightly overlapped. Season the skin side of the salmon with half the seasoning blend. Place skin side down on plastic wrap. With the remaining seasoning blend, coat the entire surface of the salmon including sides.
Loosely, but completely wrap the coated salmon. The salmon should be well covered, but with room to drain away fluids leached out during the curing process. Place on a rimmed baking sheet. You will need to place a weight on the fish like a cast iron pan, or I have found half of a wrapped watermelon to be an effective weight too. Refrigerate.
Cold cure the salmon for 3-5 days depending on the thickness of fillet, flipping and drained fluids daily. The salmon is done when it somewhat translucent, darkened, and fairly firm to the touch.
When curing is complete, rinse the fillet adequately, removing all traces of seasoning blend. Pat dry. With a very sharp knife, cut a portion for immediate use if desired, wrapping the rest in double layers of plastic to freeze for later use.
To serve, use a very sharp fillet knife to carefully slice the cold cured salmon, cutting away the skin as you go. Gravlax will keep in the refrigerator for up to two weeks, and in the freezer for a year.