Rinse the sliced rice cakes thoroughly and soak them in water for 10 minutes.
Thinly slice the beef and marinate it with sesame oil, soy sauce, and minced garlic.
Stir-fry the marinated beef in a pot, then add water and bring it to a boil.
When the broth starts boiling, add the rice cakes and cook over medium heat until they become soft.
Season to taste with soup soy sauce and salt.
Beat the egg, make a thin egg omelette, then slice it into strips.
Pour the finished tteokguk into a bowl and garnish with the sliced egg omelette, crushed seaweed, and chopped green onions.