‘Hollandse Nieuwe’ (Holland’s new herring) is the new herring of the fishing season. It is only allowed to be caught from mid May to mid July. The herring has been frozen and then laid in salt for a couple days.
In Amsterdam, fish stands sell raw herring (‘haring’), a soused raw fish with a strong taste. Dutch raw herring is hugely popular in Amsterdam. In Holland, people have been eating raw herring for over 600 years. For foreigners it might be a bit strange to eat a raw fish that has nothing to do with sushi. Raw herring is traditionally eaten with raw onions!