01 - Generously season beef short ribs on all sides with salt and black pepper.
02 - Heat a large skillet over medium-high. Sear short ribs for 2 to 3 minutes per side until browned. Transfer ribs to the slow cooker.
03 - Add chopped onion, sliced carrots, celery, and minced garlic to the skillet. Sauté for 3 to 4 minutes until slightly softened. Transfer vegetables to the slow cooker.
04 - Pour beef broth and dry red wine into the slow cooker. Stir in tomato paste and Worcestershire sauce until combined.
05 - Nestle thyme sprigs, rosemary sprigs, and bay leaves among the ribs in the slow cooker.
06 - Cover and cook on LOW for 8 hours, until meat is extremely tender and easily separates from the bone.
07 - Remove and discard rosemary, thyme, and bay leaves. Skim excess fat from the cooking liquid if necessary.
08 - If a thicker sauce is desired, blend cornstarch with water and stir into the sauce in the slow cooker. Set to HIGH and cook an additional 10 to 15 minutes until sauce thickens.
09 - Serve hot braised short ribs with vegetables and sauce over the preferred side.