01 - Season the beef chuck roast evenly with salt and black pepper on all sides.
02 - Heat 1 tbsp oil in a large skillet over medium-high heat and sear the beef roast on all sides until browned, about 4-5 minutes per side.
03 - Arrange the peeled and chopped carrots, quartered potatoes, sliced celery, onion wedges, and minced garlic in the bottom of the slow cooker.
04 - Place the seared or raw beef roast on top of the vegetables in the slow cooker.
05 - Pour the beef broth and Worcestershire sauce over the roast, then sprinkle thyme, rosemary, and add bay leaves.
06 - Cover and cook on low heat for 8 hours, or until the meat is tender and easily shredded with a fork.
07 - Transfer the roast and vegetables to a serving platter, discarding the bay leaves.
08 - Strain the cooking liquid into a saucepan. Whisk cornstarch or flour with cold water until smooth, then stir into the liquid. Simmer over medium heat, whisking constantly, until thickened, about 3 to 5 minutes.
09 - Slice or shred the roast and serve with the vegetables, pouring the savory gravy on top.