Heat a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks. Drain any excess fat.
Add the onion and garlic to the pot. Cook for 3 minutes until the onion starts to soften.
Stir in the cabbage, carrots, and potatoes. Cook for another 3 minutes to let the vegetables begin to soften.
Pour in the diced tomatoes with their juice and the beef broth. Add the thyme, salt, and black pepper.
Bring the stew to a boil, then reduce the heat to low. Cover and simmer for 20 minutes until the potatoes and carrots are tender.