Fresh and dried dill leaves are used as herbs, mainly in Germany, Poland, Finland, Norway, Sweden, the Baltic, in Russia, and in central Asia. Like caraway, its fernlike leaves are aromatic and are used to flavor many foods, such as gravlax (cured salmon), borscht and other soups, and pickles (where the dill flower is sometimes used). Dill is best when used fresh, as it loses its flavor rapidly if dried; however, freeze-dried dill leaves preserve their flavor relatively well for a few months. Dill seed is used as a spice, with a flavor somewhat similar to caraway, but also resembling that of fresh or dried dill weed. Dill oil can be extracted from the leaves, stems and seeds of the plant. Dill is the herb most often added to fish.