Flageolet (pronounced "fla-zho-LAY") are a type of shell bean grown in France and very popular in classic French cuisine.
A pale shade of green in color, Flageolet beans are sometimes known as the "caviar of beans" for their subtle flavor and the high esteem in which they are held by food lovers.
Flageolets are traditionally paired with lamb (or mutton), although they are also served with poultry and seafood recipes.
They can also be used in salads, in soups and in stews such as the classic Cassoulet recipe.
In the United States, flageolets are mostly available dried or canned, although some farmers grow any of a number of heirloom flageolet varieties. If you can get your hands on fresh ones, they can be simmered gently in stock flavored with mirepoix and bacon. Unlike dried beans, fresh flageolets can be added directly to simmering water (or stock).
Dried flageolets need to be soaked for a bit, and there's disagreement about how long. Some cooks recommend at least six hours, or even overnight. The problem with this is that the beans can start to ferment if soaked for too long, which alters their delicate flavor. If the beans are fresh (meaning recently dried, as in within the past 12 months), it is probably sufficient to soak them for an hour or two, and then simmer them until tender.