Pat the beef chuck roast dry with paper towels. Season all sides with salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat. Sear the roast on all sides until browned, about 3-4 minutes per side. Remove from heat.
Place the sliced onion, carrots, and potatoes in the bottom of the crock pot.
Place the seared roast on top of the vegetables in the crock pot.
In a small bowl, whisk together the beef broth, Worcestershire sauce, tomato paste, minced garlic, dried thyme, and dried rosemary.
Pour the broth mixture evenly over the roast and vegetables.
Cover the crock pot with the lid and cook on low for 8 hours, or until the beef is tender and easily shredded with a fork.
Remove the roast and vegetables from the crock pot and transfer to a serving platter. Let the roast rest for 5 minutes before slicing.
Optional: To thicken the cooking liquid, pour it into a saucepan and simmer over medium heat until reduced to desired consistency. Serve the sauce alongside the roast beef and vegetables.