I steam sweet potatoes (with skins. They come off easier when hot). Or peel them before steaming.
Whip them like mashed potatoes. Add some crushed pineapple and/or dried cranberries. A little nutmeg and butter. If you like them a little creamier, then add some cream cheese or vanilla yogurt for the consistency you like.
Sometimes I add some cinnamon applesauce for a different taste.