Cranberry Bean Gratin

Beans cooked and served simply seasoned—like the cannellini beans in the previous recipe with garlic and rosemary—is only one of a great many bean dishes—soups, gratins, purées, and more—that are tastier when their primary flavoring comes after an initial cooking. I sometimes add garlic or herbs or even a bit of onion while the beans are cooking the first time, but I find that good flavor is most prominent when it’s added after the primary cooking. Added flavor can mean anything from a dash of olive oil to a complex tomato sauce, depending on the dish. For example, in the classic Italian dish called fagioli all’uccelletto (which means beans seasoned like a small bird), the cooked beans are simmered in a garlicky tomato sauce with plenty of sage. An example from Mexican cuisine is frijoles refritos, beans which, after an initial cooking, are fried in lard with garlic and sautéed onions, and then mashed. (There are exceptions to every rule, and one that comes immediately to mind is that when something like a ham hock or a prosciutto bone is used to flavor beans, it can be added at the beginning to cook slowly with the beans throughout their cooking.) The beans should be drained of most of their liquid before final flavorings are added. (Save the bean water to make a tasty soup base or to moisten a gratin as it cooks.) Once the beans are ready, stir in the flavorings. Continue to cook them together for at least 10 minutes or so, to allow the flavors to infuse the beans. To make gratins like the one that follows, first sauté onions, carrots, and celery together. To make sure they contribute their full flavor, season the vegetables to taste before adding them to the beans. Beans are very lean and the addition of a flavorful oil or fat makes them taste even better.