Pat the beef chuck roast dry and season it generously with salt and pepper on all sides.
Heat olive oil in a large skillet over medium-high heat. Sear the roast for 3 to 4 minutes per side until browned.
Place the sliced onion, carrots, and potatoes in the bottom of a slow cooker. Add minced garlic on top.
Set the seared roast on the vegetables. Stir tomato paste into the beef broth and pour the mixture over everything.
Sprinkle thyme and rosemary over the contents. Cover and cook on low for 8 hours.
Remove the roast and vegetables to a serving platter. If desired, thicken the remaining liquid in a skillet over medium heat to make gravy.