Sear: Season beef with salt and pepper. Heat olive oil in a skillet and sear meat for 3–4 minutes on each side until brown. Transfer to the crock pot.
Layer: Add the potatoes, carrots, and chopped onions around the beef.
Pour: Whisk dry onion soup mix into the beef broth and pour into the slow cooker.
Cook: Cover and cook on LOW for 7 to 8 hours (or HIGH for 4–5 hours).
Gravy: Remove beef and veggies. Whisk cornstarch slurry into the boiling juices for 5 mins to thicken. Shred beef, pour gravy on top, and serve!