The word Rollmops, borrowed from German, refers to a pickled herring fillet rolled (hence the name) into a cylindrical shape around a piece of pickled cucumber or an onion. The whole thing is held together with one or two small wooden skewers. Rollmops are usually bought ready-to-eat in glasses. The marinade additionally contains water, white vinegar, salt, a bit of sugar or other sweetening agent, onion rings, peppercorns and mustard seeds. Rollmops can be eaten cold, without unrolling, or on bread.