Tteokguk

Tteokguk or sliced rice cake soup is a traditional Korean dish eaten during the celebration of the Korean New Year. The dish consists of the broth/soup (guk) with thinly sliced rice cakes (tteok). Eating tteokguk on New Year's Day is traditionally believed to grant good luck for the year and confer one sal (a year of age). It is usually garnished with thin julienned cooked eggs, marinated meat, gim (김), and sesame oil (참기름). The origin of eating tteokguk on New Year's Day is unknown. However, tteokguk is mentioned in the 19th-century book of customs Dongguksesigi (동국세시기; 東國歲時記) as being made with beef or pheasant used as the main ingredient for the broth, and pepper added as seasoning. The book also mentions the custom of having a bowl of tteokguk in the morning of New Year's Day to get a year older, and the custom of saying "How many bowls of tteokguk have you eaten?" to ask a person's age. In the book The Customs of Joseon written in 1946 by historian Choe Nam-seon, the New Year custom of eating tteokguk is speculated as being originated from ancient times. The white tteok signifying purity and cleanliness have been eaten during that specific day and it became a ritual to start off the New Year for good fortune.

Source: Wikipedia