01 - Generously season beef short ribs on all sides with salt and pepper.
02 - Heat a large skillet over medium-high heat. Brown short ribs on all sides for 2 to 3 minutes per side. Transfer browned ribs to slow cooker.
03 - Add chopped onion, sliced carrots, celery, and minced garlic to the skillet. Sauté for 3 to 4 minutes until vegetables are softening. Add to slow cooker.
04 - Pour beef broth and red wine into the slow cooker. Stir in tomato paste and Worcestershire sauce.
05 - Nestle thyme sprigs, rosemary sprigs, and bay leaves among the ingredients in the slow cooker.
06 - Cover and cook on LOW for 8 hours, or until ribs are extremely tender and the meat is nearly falling off the bone.
07 - Remove and discard herb sprigs and bay leaves. Skim off excess fat from the top if necessary.
08 - If a thicker sauce is desired, mix cornstarch and water until smooth. Stir into the slow cooker and cook on HIGH for 10 to 15 minutes, or until the sauce has thickened.
09 - Plate beef short ribs with their sauce and vegetables while hot.