There are almost as many names for casseroles and gratins as there are recipes. It’s a rich genre of cooking, including everything from Italian lasagna to Indian biryani to American tuna casserole. It’s also an improvisational genre, with the best casseroles being mixes of leftovers and simple food, like the French peasant food the onion panade. Here are about a dozen casseroles from The Kitchn, with one layered baked dessert thrown in for good measure!