Dill is an herb in the celery family, and both its leaves and seeds are used to flavor foods. Its stems sport wispy, feathery leaves that have a soft, sweet taste. Dill's flavor does not survive heat well, so it's best to add it at the end of cooking. Dill lends a delicate, licorice-like flavor to eggs and cheese, potatoes and cream, and fish and fowl. It's also a popular addition to pickles and salad dressings.