The French phrase au gratin literally means "with the burnt scrapings from the pan," though in practice it means to top a food with breadcrumbs and cheese. Sweet potatoes au gratin is delicious and simple to make; this recipe is a lighter alternative to traditional recipes that call for whole milk or heavy cream, though you could certainly use them in place of the broth in the dish. And to make the prep work on yourself a bit easier, forgo peeling the potatoes. The skins are perfectly edible and contain a lot of nutrients; plus, the peels add a bit of visual interest. After a short time in the oven, this bubbly, gooey dish is ready to be spooned out and eaten up!