Bring a large pot of water to a boil and add a generous pinch of salt. Carefully lower the whole cabbage into the water, cover, and simmer for 8-10 minutes, turning once, until the outer leaves are softened. Remove the cabbage and let it cool slightly. Gently peel off 12-14 large leaves, trimming the thick central vein with a knife to make them pliable. Set leaves aside. Reserve any remaining cabbage for another use.