Pickled herring
Pickled herring is a traditional way of preserving herring as food by pickling or curing. Most cured herring uses a two-step curing process: it is first cured with salt to extract water; then the salt is removed and the herring is brined in vinegar, salt, and sugar solution, often with peppercorn, bay leaves, raw onions, and so on. Additional flavourings include sherry, mustard and dill, while other non-traditional ingredients have also begun being included in recent years. Pickled herring remains a popular food or ingredient to dishes in many parts of Europe including Scandinavia, Great Britain , the Baltic, Eastern and Central Europe, as well as the Netherlands. It is also popular in parts of Canada such as British Columbia and Newfoundland. It is also associated with Ashkenazi Jewish cuisine, becoming a staple at kiddushes and social gatherings. Pickled herring is one of the twelve dishes traditionally served at Christmas Eve in Russia, Poland, Lithuania, and Ukraine. Pickled herring is also eaten at the stroke of midnight on New Year's Eve to symbolize a prosperous New Year in Poland, the Czech Republic, Germany, and parts of Scandinavia. History. Pickled herrings have been a staple in Northern  Europe since medieval times, being a way to store and transport fish, especially necessary in meatless periods like Lent. The herrings would be prepared, then packed in barrels for storage or transportation. In 1801 Dutch fishermen amongst the prisoners of war in the Norman Cross Prison were sent to Scotland to teach the Scottish herring fishermen how to cure fish using the Dutch method. Geographic distribution. In the Nordic countries, once the pickling process is finished and depending on which of the dozens of herring flavourings (mustard, onion, garlic, lingonberries etc.) are selected, it is eaten with dark rye bread , crisp bread, sour cream, or potatoes. This dish is common at Christmas, Easter and Midsummer, where it is frequently accompanied by spirits like akvavit. Soused herring ("maatjesharing" or just "maatjes" in Dutch) is an especially mild salt herring, which is made from young, immature herrings. The herrings are ripened for a couple of days in oak barrels in a salty solution, or brine. In English, a "soused herring" can also be a cooked marinated herring. Rollmops are pickled herring fillets rolled (hence the name) into a cylindrical shape around a piece of pickled gherkin or an onion. They are thought  to have developed as a special treat in 19th century Berlin, and the word borrowed from the German. Fish cured through pickling or salting have long been consumed in the British Isles. Like jellied eel, it was primarily eaten by, and is sometimes associated with, the working-class. Kipper is a dish eaten in Great Britain, Ireland, and parts of Canada. It consists of a split open herring, pickled or salted, and cold-smoked. Red herring is similar to kippers but is whole and ungutted; it is more heavily salted and is smoked for 2-3 weeks. The main UK  export markets are Europe and West Africa. Pickled herring, especially brined herring, is common in Russia and Ukraine, where it is served cut into pieces and seasoned with sunflower oil and onions, or can be part of herring salads, such as dressed herring (, , lit. 'herring under a fur coat'), which are usually prepared with vegetables and seasoned with mayonnaise dressing. Brined herring is common in Ashkenazi Jewish cuisine, perhaps best known for vorschmack salad known in English simply as "chopped herring" and as schmaltz herring in Yiddish. In Israel it is commonly known as "dag maluach" which means "salted fish . Pickled herring can also be found in the cuisine of Hokkaidō in Japan, where families traditionally preserved large quantities for winter. In Nova Scotia, Canada, pickled herring with onions is called solomon gundy" and is quite popular. (Not to be confused with the Jamaican pickled fish pâté of the same name, or the DC character). "Bismarck herring" (German "Bismarckhering") is the common name for pickled herring in Germany, and is sometimes sold elsewhere under that name. There are various theories as to why the product is associated with Bismarck. Nutritional content. Pickled herring is rich in tyramine and thus should  be avoided in the diet of people being treated with an antidepressant monoamine oxidase inhibitor. As with fresh herring, pickled herring is an excellent natural source of both vitamin D3 and omega-3 fatty acids. It is also a good source of selenium and vitamin B12. 100 grams may provide 680 IU of vitamin D, or 170% of the DV, as well as 84% of the DV for selenium, and 71% of the DV for vitamin B12.