If you’ve caught your own salmon or have a generous friend, you may have to gut the salmon yourself. To do this, notice the small anal opening on the bottom of the salmon about ¼ the length of the fish away from the tail. Insert a sharp knife into this opening and slide the blade up along the belly all the way to the base of the head. Stick the knife into the belly just deep enough to cut through it—not deeper or you’ll cut up the viscera and make the job needlessly messy. Reach into the belly opening and pull out the viscera, cutting with a sharp knife the membranes that hold the viscera attached to the rest of the fish. Rinse out the inside of the salmon.