Jellied eels

Jellied eels is a traditional English dish that originated in the 18th century, primarily in the East End of London. The dish consists of chopped eels boiled in a spiced stock that is allowed to cool and set, forming a jelly. It is usually served cold. Eels were historically a cheap, nutritious, and readily available food source for the people of London; European eels were once so common in the Thames that nets were set as far upriver as London itself, and eels became a staple for London's poor. The earliest known eel, pie and mash houses opened in London in the 18th century, and the oldest surviving shop, M.Manze, has been open since 1902. At the end of the Second World War, there were around 100 eel, pie and mash houses in London. In 1995, there were 87.

Source: Wikipedia