Preheat oven to 325°F (165°C). Season the beef generously with salt and pepper.
Heat olive oil in a large Dutch oven over medium-high heat. Sear the roast on all sides until deeply browned. Remove and set aside.
Add onion, carrots, and garlic to the pot. Cook until softened. Stir in tomato paste.
Return the roast to the pot. Add beef broth, thyme, and bay leaf. Liquid should come halfway up the meat.
Cover and transfer to the oven. Cook for about 3 hours, until the beef is fork-tender.
Remove from oven and let rest for 15 minutes. Discard bay leaf and thyme sprigs.
Slice or shred the beef and serve with vegetables and pan juices.