Prep wrap. Lay out two long pieces of plastic wrap on a rimmed baking sheet. Overlap the two pieces of plastic wrap 2 inches and extend past the baking sheet 6 inches on the long sides (to allow to fully wrap over the salmon).

Make seasoning. In a large bowl, combine the salt, brown sugar, coriander, and dill. Sprinkle 1 cup of the salt and sugar mixture on the plastic wrap, making it extend 1 inch past where the salmon will lay.

Season salmon. Place the salmon skin-side down on top of the salt and sugar mixture. Sprinkle the remaining salt and sugar on top of the salmon, making sure there are no exposed pieces of the salmon remaining.

Wrap and cure. Lift up the ends plastic wrap and fully cover the salmon, making sure that no ends of the wrap are hanging over the edges of the baking sheet. Place in the refrigerator for 24 hours, flipping the salmon over so it is skin side up after the first 12 hours.

Remove and soak salmon. Remove the salmon from the fridge and unwrap. Carefully lift the salmon from the salt and sugar mixture and gently shake off any excess. Place the salmon in a vessel (such as a 9x13 pan) and fill with cool water until the salmon is covered. Allow the salmon to soak in the fridge for 15-20 minutes.

Develop salmon exterior. Place the salmon on a flat, elevated surface that will allow the air to circulate on all sides of the salmon (like a roasting or cooking rack) over a rimmed baking sheet and place in the fridge for at least 4 hours (or up to 8 hours) to develop a tacky coating on the exterior called a pellicle.

Prepare your smoker for cold smoking. Your smoker needs to be under 80 degrees F.

Smoke. Place the salmon directly into the smoker, skin side down. Close the lid and smoke for 18-24 hours.

Chill and serve. Remove the salmon from the smoker. Chill completely in the fridge. Serve as desired.