Pat the beef chuck roast dry with paper towels. Season all sides with kosher salt and black pepper.
Heat olive oil in a large skillet over medium-high heat. Sear the roast on all sides until browned, about 3-4 minutes per side. Transfer the roast to the slow cooker.
In a small bowl, whisk together gluten-free beef broth, gluten-free Worcestershire sauce, and tomato paste until combined.
Add minced garlic, onion wedges, carrots, celery, and baby potatoes to the slow cooker around the roast.
Pour the broth mixture over the roast and vegetables.
Sprinkle dried thyme and dried rosemary evenly over the roast and vegetables. Add bay leaves to the slow cooker.
Cover and cook on low for 8 hours, or until the meat is tender and easily shredded with a fork.
Remove bay leaves before serving. Serve the pot roast sliced or shredded with the cooked vegetables and spoon some cooking liquid over the top.