Pat the roast dry and season all over with your favorite beef seasoning. For extra flavor, sear all sides in butter or olive oil before adding it to the crockpot. Searing is optional.
Place the raw onion, garlic, carrots, celery underneath the chuck roast and then potatoes around the roast. I used 7qt crockpot.
Whisk the tomato paste into the beef broth and pour over the roast. Add thyme. The meat doesn’t need to be submerged.
Cover and cook on LOW for 8–10 hours or HIGH for 5–6 hours. These are estimates—if the roast doesn’t pull apart easily with a fork, keep cooking until tender.
When your chuck roast is done, remove the beef and mix your cornstarch slurry and add into crockpot and stir until thickened. Discard the thyme stems and add beef back in. Set on high for 5-10 minutes.
Pull the roast into tender pieces and serve with the potatoes and vegetables. Spoon that gravy over everything!
