This pungent member of the ginger family adds a citrusy tang to Vietnamese dishes, and is often used with fish. Like its first cousins, turmeric, ginger, galanga is thought to provide medicinal value along with its extraordinary aroma and flavor. Fresh galanga resembles ginger, but it is rounded and shiny, with thin, dark concentric rings. Frozen galanga is widely available, whole or sliced, while dried galanga comes sliced or ground. Frozen and dried galanga work well, but the powdered form is merely dust. You can replace galanga with fresh ginger in recipes for a different, but harmonious flavor and scent.