01 - Season the beef chuck roast evenly with kosher salt and black pepper.
02 - Place sliced onion, carrot chunks, celery chunks, and smashed garlic at the bottom of the slow cooker.
03 - Position the seasoned beef roast on top of the arranged vegetables.
04 - Sprinkle dried thyme, dried rosemary, and add the bay leaf. Pour beef broth and Worcestershire sauce over the roast.
05 - Cover and cook on low heat for 8 hours until the beef is tender and easily shredded with a fork.
06 - Remove the beef and vegetables from the slow cooker to a serving platter and tent with foil to retain warmth.
07 - Skim fat from cooking juices. In a small bowl, combine cornstarch or flour with water to create a slurry, then stir it into the juices.
08 - Turn the slow cooker to high and cook uncovered for 10 to 15 minutes until the gravy thickens.
09 - Slice or shred the beef roast, serve alongside the cooked vegetables, and ladle the gravy over the top.