In a large pot over medium-high heat, place beef and cover with broth. Add spice packet, thyme, bay leaves, and peppercorns. Bring to a boil, then reduce heat to medium-low and bring to a simmer. Cover and cook, adding water to keep beef covered as needed, until tender, about 3 hours.
Add potatoes and carrots and return to a boil. Cook 15 minutes. Add cabbage and continue to boil until vegetables are tender, about 10 minutes more.
Transfer meat to a cutting board and let rest 10 minutes. Drain vegetables in a colander. Thinly slice meat, then transfer to a platter. Arrange vegetables alongside.
