Wikipedia
Miyeok guk is a Korean soup made from miyeok, a sea vegetable. Miyeok guk is most commonly made from a mussel based broth, but anchovy, beef, clam or oyster can also be used to make the broth. Korean soy sauce, sesame oil, garlic, and sometimes onions, scallions, salt, roasted sesame seeds, and dried or pickled shrimp are flavorings that can be used in miyeok guk. Miyeok guk is not spicy.
Miyeok guk is consumed by Korean women after giving birth. In Korean culture, miyeok is widely believed to contain a high content of calcium and iodine, nutrients that are important for nursing mothers. Many women also eat miyeok guk during pregnancy. Miyeok guk is eaten on birthdays, typically for breakfast. At a traditional birthday party meal, guests are typically served miyeok guk along with rice cakes and other celebratory foods. Koreans eat miyeok guk on their birthdays in order to remember their mothers and appreciate how their mothers ate miyeok guk to recover and provide nutrients to their babies. Miyeok guk is also eaten during the rest of the year. It is a very common side soup served with rice at home or and in restaurants.
To prepare miyeok guk, dried miyeok is soaked in cold water until soft, washed, boiled in an anchovy stock with shellfish or beef, and then seasoned with soy sauce, minced garlic and sesame oil.