Buy salmon steaks that are at least ¾ inch [2 cm] thick—thinner steaks won’t hold their shape. Unless your steaks come from near the salmon’s tail, they’ll have two stomach flaps hanging down on either side. Slide a paring knife along the inside of the two flaps and separate the bones from the flesh. Cut along the side of the bones that run up toward what was once the back of the salmon, following the bones all the way around the spinal column until you reach the top of the steak. Cut all the way to the top of the steak toward the skin, but don’t cut through the skin. Repeat on the other side of the spinal column until you’ve removed all the spinal bones and ribs. Run your finger along both sides of the steaks to feel for any small pin bones that are left embedded in the flesh. Pull these out with tweezers or needle-nose pliers. Carefully cut away about 2 inches [5 cm] of the skin that wraps around one side of the stomach flaps so that raw skin isn’t left on the inside of the medallion when this outer flap is wrapped inside the medallion. Fold the stomach flaps inside the medallion and tie it into a round shape with string.