Over medium heat add butter and onion to large sautee pan. Cook for about 5 minutes or until onion is translucent
Add 4 cups shredded cabbage, thinly sliced apple, 2 tbsp apple cider vinegar, 2 tbsp water and a pinch of salt.
Cover pot and stir occasionally, adding additional water if there is no moisture left. Cook until cabbage is very tender, about 30 minutes.
Season with additional salt, vinegar or black pepper if desired
