Season the beef chuck roast evenly with salt and black pepper on all sides.
Heat the olive oil in a large skillet over medium-high heat.
Sear the roast in the hot oil for 4-5 minutes on each side until browned. Remove from heat.
In a medium bowl, combine the cream of mushroom soup, beef broth, minced garlic, dried thyme, and dried rosemary. Stir until smooth.
Place the sliced onion, carrots, and potatoes in the bottom of the slow cooker.
Set the seared roast on top of the vegetables in the slow cooker.
Pour the cream of mushroom soup mixture evenly over the roast and vegetables.
Cover and cook on low for 8 hours, or until the beef is tender and easily shredded with a fork.
Once cooked, remove the roast and vegetables from the slow cooker and let the roast rest for 5 minutes before slicing.
Serve the sliced pot roast with the cooked vegetables and spoon the mushroom sauce over the top.