01 - Pat the beef dry and season all sides evenly with kosher salt and black pepper.
02 - Heat a large skillet over medium-high and sear the roast for 3 to 4 minutes per side until well browned. Transfer the seared roast to the slow cooker.
03 - Arrange carrots, onion, garlic, celery, and potatoes, if using, around the beef in the slow cooker.
04 - In a bowl, whisk together beef broth, red wine if used, tomato paste, Worcestershire sauce, thyme, rosemary, and bay leaves. Pour the mixture evenly over the beef and vegetables.
05 - Cover and cook on LOW for 8 hours or on HIGH for 5 hours, until beef is tender and vegetables are fully cooked.
06 - Transfer the beef and vegetables to a serving platter and discard the bay leaves.
07 - Mix cornstarch and cold water in a small bowl. Stir into the slow cooker and cook on HIGH for 5 to 10 minutes until the sauce thickens.
08 - Slice or shred the beef and serve alongside the vegetables with the thickened sauce.