Evenly spread shio koji on both sides of the salmon filets. Store in a re-sealable plastic bag or (non-reactive) glass or plastic container. Marinate 15 to 30 minutes or overnight. NOTE: If you are pressed for time, simply spread shio koji over the salmon and cook.
Prepare a baking sheet by lining it with foil and then placing a metal broiler rack on top. Spray the broiler rack with cooking spray to prevent the fish from sticking.
Set the oven to broil on high and grill the fish for 6 to 8 minutes on one side. Turn fish over and broil an additional 3 minutes until cooked through. Time may vary slightly depending on the thickness of the filets.
Recipe by Bebe Love Okazu at https://bebeloveokazu.com/2014/06/30/shio-koji-salmon/