Duk mandu guk is a variation of duk guk (rice cake soup), that includes dumplings. You can make your own mandu for this (or use some that you made previously and froze), or just buy frozen dumplings at the grocery store.
2 cups of sliced rice cakes, you can find this at a Korean grocery
15-20 pieces of readymade dumplings (small size) - you can buy frozen dumplings or you can make your own using this mandu recipe.
1 tsp anchovy powder (myulchi garu 멸치 가루)
1 tsp minced garlic
3 cups of boiled beef bone soup (sagolguk) or you can substitute chicken broth/beef broth
1 bunch green onion chopped small
1 tsp kosher salt
2 sheets of roasted roasted seaweed (gim 김)
Soak sliced rice cakes for 5-10 minutes.
Beat egg whites and yolks separately, and add pinch of salt and pepper to both. Pour the egg whites into a heated frying pan. The goal is to have thin sheets of egg like crepes. Repeat with the yolks. Cut the thin egg sheets it into narrow matchstick-style slices.
Roast the dried seaweed sheets over a burner (a few seconds on each side, until it changes from dark green/black to light greenish) or put into a toaster oven. Slice the roasted seaweed into thin strips as well, or crush with your hand. Put into a serving dish.
Boil the soup stock (either the beef bone or pre-made beef or chicken stock) with anchovy powder and garlic.
Add rice cakes, dumplings and salt and bring to a boil. Cook on medium heat for about 15 minutes or until the dumplings start floating - add chopped green onion and turn the heat off.
For each serving, get a large bowl. Scoop up some soup with enough rice cakes and dumplings, garnish with yellow and white egg threads and some more chopped green onions. Serve the roasted seaweed at the table for people to individually add into their bowl throughout the meal.