01 - Sprinkle salt and black pepper evenly over all sides of the beef short ribs.
02 - Heat a large skillet over medium-high. Brown short ribs on all sides, about 2 to 3 minutes per side, and transfer to slow cooker.
03 - Add chopped onion, carrots, celery, and minced garlic to the skillet. Sauté for 3 to 4 minutes until slightly softened, then transfer to the slow cooker.
04 - Pour in the beef broth and dry red wine. Add tomato paste and Worcestershire sauce to the slow cooker and stir to combine.
05 - Place fresh thyme, rosemary, and bay leaves into the slow cooker with the other ingredients.
06 - Cover and cook on LOW for 8 hours, or until the short ribs are fork-tender and meat easily detaches from the bone.
07 - Remove the herb sprigs and bay leaves. Skim excess fat from the surface if necessary. For a thicker sauce, stir in cornstarch-water mixture and cook on HIGH for 10 to 15 minutes until thickened. Serve the short ribs hot with sauce and vegetables.