Meanwhile, bring a large saucepan of water to a boil. Remove any damaged outer leaves from the cabbage. With a sharp knife, core the cabbage, cutting a hole at least one inch wide and deep. Place the cabbage in the saucepan, cored end down, and boil for 12 minutes. With 2 large spoons, transfer the cabbage to a large bowl of ice water and let cool slightly. Carefully peel off as many softened leaves as you can without tearing them. Return the cabbage to the saucepan and repeat the process, if necessary, until you have 16 whole leaves.