Solyanka
Solyanka is a thick and sour soup of Russian origin. It is a common dish in Russia, Ukraine, Belarus, the Baltic states, and other post-Soviet states and other parts of the former Eastern Bloc. It was one of the most reliably available dishes in the former East Germany (German: Soljanka). The original name "selyanka" can be translated to "settler's soup" in English. There are many theories about the origin of the name, but a common one is that the soup was often eaten after the wedding before the newlyweds "settled down" and started their new life together. Other translations of "selyanka" include "food of the villager" or "villager’s stew". Later the name transformed to "solyanka" using the word "sol" (salt) as a reference to the soup's saltiness. Due to its astringent sour taste that is believed to relieve a hangover solyanka has also earned the nickname "hangover soup".
Source: Wikipedia