How do you make patangguk?

Patangguk is a traditional Korean dish made with thinly sliced beef, vegetables, and a savory broth. To prepare it, simmer beef in a pot with water until tender, then add sliced onions, garlic, and any desired vegetables like mushrooms or spinach. Season the broth with soy sauce, sesame oil, and pepper, allowing the flavors to meld. Serve hot, garnished with green onions and sesame seeds, typically enjoyed with rice.