01 - Sprinkle beef short ribs evenly with salt and black pepper on all sides.
02 - Heat a large skillet over medium-high and brown the short ribs on all sides for 2 to 3 minutes per side. Transfer the seared short ribs to the slow cooker insert.
03 - Add chopped onion, carrots, celery, and minced garlic to the same skillet. Sauté for 3 to 4 minutes until slightly softened. Transfer vegetables to the slow cooker.
04 - Pour beef broth and red wine into the slow cooker. Add tomato paste and Worcestershire sauce, stirring to combine.
05 - Place thyme sprigs, rosemary sprigs, and bay leaves into the slow cooker.
06 - Cover and cook on LOW setting for 8 hours, or until the short ribs are exceptionally tender and the meat falls off the bone.
07 - Remove and discard herb sprigs and bay leaves. Skim excess fat from the surface, if needed.
08 - If a thicker sauce is desired, stir cornstarch and water mixture into the slow cooker. Increase heat to HIGH and cook for 10 to 15 minutes until thickened.
09 - Serve hot with sauce and vegetables over mashed potatoes, polenta, or with crusty bread as desired.