In a medium bowl, combine the granulated sugar, kosher salt, and coarsely ground multi-color peppercorns. Mix well until all ingredients are evenly distributed.
Stir in the liquid smoke, finely chopped dill, and chili pepper flakes to the cure mixture.
Place the salmon fillet skin-side down in a glass baking dish.
Generously sprinkle the cure mixture evenly over the salmon, ensuring every inch is covered.
Cover the salmon with parchment paper and then wrap it tightly with plastic wrap. Place a weight on top to help compress the salmon during curing.
Refrigerate the salmon for 48 to 72 hours, checking daily.
After the curing period, carefully unwrap the salmon and rinse off the cure mixture under cold water. Pat the salmon dry with paper towels.
Using a sharp knife, slice the salmon thinly at a diagonal angle.
