Agar, a shortened version of the Malay agar agar, is a mixture of several different carbohydrates and other materials that has long been extracted from several genera of red algae. It’s now manufactured by boiling the seaweeds, filtering the liquid, and freeze-drying it in the form of sticks or strands, which are readily available in Asian groceries. The solid pieces of agar can be eaten uncooked as a chewy ingredient in cold salads, soaked and cut into bite-sized pieces. In China agar is made into an unflavored gel that’s sliced and served in a complex sauce; it’s also used to gel flavorful mixtures of fruit juice and sugar, and stews of meats, fish, or vegetables. In Japan agar is made into jellied sweets.