This manduguk has a light beef flavor. It's just rich enough to make your lips a little sticky and you'll pick up on a subtle sweetness from the onions at the end. The fish sauce and sea salt impart umami in the soup, but it shouldn't overwhelm the beef broth or the other ingredients. All the add-ins, particularly the shredded beef, sesame oil, and nori, add savoriness without dominating each other for flavor. Serve with kimchi or steamed rice.
Mandu refers to Korean stuffed dumplings. Manduguk is made only with dumplings while tteok-manduguk is a rice cake soup made with dumplings. Both versions will come up when you search for this soup. North Koreans make this soup with dumplings and in South Korea, where rice grows more favorably, rice cakes are added.
There are two types of broth you can make for this soup, beef or anchovy. I added ginger to my broth, but I'm pretty sure that is not a traditional ingredient. The soup is traditionally seasoned with soup soy sauce (a byproduct of fermented soy bean paste) or fish sauce. You can use whatever flavor dumplings you like.
Use your favorite type of store-bought dumplings.