Heat olive oil in a large skillet over medium-high heat.
Season the beef chuck roast with salt and black pepper on all sides.
Sear the roast in the hot skillet for 3-4 minutes on each side until browned. Remove from heat.
Place the carrots, potatoes, and sliced onion in the bottom of the slow cooker.
Add the minced garlic on top of the vegetables.
Place the seared roast on top of the vegetables in the slow cooker.
Sprinkle the ranch dressing mix evenly over the roast.
Pour the beef broth around the roast, avoiding washing off the ranch seasoning.
Cover the slow cooker with the lid and cook on low for 8 hours, or until the meat is tender and easily shredded with a fork.
Remove the roast and vegetables from the slow cooker and let rest for 5 minutes before slicing or shredding.
Serve the pot roast with the cooked vegetables and spoon some of the cooking juices over the top.