In a large bowl, combine the coarse kosher salt, granulated sugar, crushed peppercorns, coriander, and red pepper flakes (if using). Mix well until all ingredients are evenly distributed.
Place the salmon skin-side down on a clean work surface. Check for any pin bones and remove them with tweezers. Pat the salmon dry with paper towels to remove excess moisture.
Spread a layer of the cure mix over the salmon, ensuring that the fish is fully coated. Sprinkle the lemon zest and half of the chopped dill over the salt-sugar mixture. Reserve the remaining dill for garnishing.
Wrap the salmon tightly in plastic wrap to prevent air from entering. Place the wrapped salmon in a baking dish or tray and weigh it down with heavy cans or weights. This will help extract moisture and aid in the curing process.
Refrigerate the salmon for 48 to 72 hours. The longer you let it cure, the firmer and saltier it will become. Turn the salmon every 12 hours to ensure even curing.
Once the curing time is complete, remove the salmon from the wrap and rinse it under cold water to remove the excess cure. Pat dry with paper towels. Using a sharp knife, slice the salmon thinly at a slight angle, creating beautiful, translucent pieces.
Arrange the sliced gravlax on a platter, garnished with the reserved dill. Serve with bagels, cream cheese, capers, and red onion for a classic presentation. Enjoy your homemade Cured Salmon Gravlax Recipe!
