Pat the beef dry with paper towels and season generously with salt and pepper on all sides. Place it in your slow cooker.
In a small bowl, whisk together the balsamic vinegar, soy sauce, brown sugar, beef broth, minced garlic, Worcestershire sauce, thyme, and rosemary.
Pour the glaze mixture over the beef. Cover and cook on LOW for 7-8 hours or on HIGH for 4-5 hours. The beef is done when it shreds easily with a fork.
Remove the beef to a serving platter. Pour the remaining liquid from the slow cooker into a small saucepan over medium-high heat. Simmer for 5-10 minutes until it reduces and becomes a thick, sticky glaze.
Shred or slice the beef. Drizzle the thickened glaze over the top and garnish with fresh herbs. Serve with mashed potatoes or crusty bread to soak up the juices!
