Koreans eat a rice cake soup called tteokguk on Lunar New Year's Day, but not many people realize how many regional variations there. The difference usually comes down to ingredients used to make the broth, or whether dumplings are added or not.
The most common base for the broth is beef, but it is only natural for people to use ingredients that are most easily found in their region.
Traditionally, people in northern parts including Pyongyang only ate dumpling soup, while people in southern areas ate ttoekguk that is similar to the standard version today. In central parts like Gyeonggi and Chungcheong provinces, people ate the dish with both rice cakes and dumplings.
In southern coastal towns like Geoje, Masan and Tongyeong in South Gyeongsang Province, people put oysters in the soup, and Gangneung on the eastern coast of Gangwon Province is famous for its tofu, so tofu and dumplings are added.
In South Jeolla Province, people traditionally add pulled chicken in soy sauce, and in the Chungcheong provinces locals use flour dough instead of rice cakes.
In the past, tteokguk in Gyeongsang Province was unique because the rice cakes were shaped like coins rather than oval, probably suggesting their wishes for wealth in the New Year.
The reason the rice cakes changed from round to oval is not certain. Han Bok-ryeo, an expert on royal court cuisine, says, "In practical terms, it's easier to slice rice cakes at a slanted angle rather than perpendicularly. Also I suppose an oval shape looks bigger, and therefore makes a bowl of tteokguk look fuller."