Preheat your oven to 300 degrees F.
Melt the butter in a large Dutch oven or heavy-bottomed pot over medium heat. Add the onion, celery, and sauté for about 5 minutes until the vegetables are softened.
Season the chuck roast generously with salt, pepper, garlic powder, thyme, and rosemary. Add the roast to the pot with vegetables and brown on all sides for about 5 minutes.
Once the meat is nicely browned, pour in the gravy or beef broth, covering all of the ingredients with liquid.
Place a lid on top of the pot and transfer it to the oven. Cook for 2 ½ to 3 hours, until the roast is tender enough to be easily pulled apart with a fork.
About an hour before the roast is done cooking, add in the potatoes and carrots. Stir everything together and ensure all the vegetables are covered with liquid. Replace the lid on the pot and allow it to cook for the remaining time.
When finished cooking, pull out the roast and vegetables and serve.