01 - Pat the beef roast thoroughly dry with paper towels. Season generously on all sides with kosher salt and freshly ground black pepper.
02 - In a large skillet over medium-high heat, warm the olive oil. Sear the roast on all sides until deeply browned, approximately 4 minutes per side. Transfer the seared beef to the slow cooker.
03 - Place carrots, parsnips, potatoes, onions, celery, and garlic into the slow cooker, arranging them around and beneath the beef roast.
04 - In a small bowl, whisk together the beef broth, red wine (if using), tomato paste, and Worcestershire sauce until smooth and well combined.
05 - Pour the liquid mixture evenly over the beef and vegetables. Sprinkle thyme, rosemary, and bay leaves across the top.
06 - Cover and cook on low setting for 8–9 hours, or on high setting for 4–5 hours, until the beef is fork-tender and vegetables are completely cooked through.
07 - Discard bay leaves and any fresh herb stems. Slice or shred the beef as desired. Serve with vegetables and pan juices.