Instructions:
- Combine salt, pepper, and flour on a plate. Thoroughly coat the dry chuck roast in the mixture, shaking off any excess.
- Heat oil in a large skillet over medium-high heat until shimmering. Sear the roast aggressively on all sides until a deep brown crust forms (about 3-4 minutes per side).
- Remove the roast to the slow cooker. If using wine, pour it into the hot skillet and scrape up all the brown bits (fond). Let the wine reduce slightly (about 2 minutes).
- Pour the deglazed wine (or broth if skipping wine) into the slow cooker around the roast. Add the beef broth, Worcestershire sauce, onion, carrots, celery, smashed garlic, tied thyme bundle, and bay leaves. The liquid should cover about two-thirds of the roast.
- Cover the slow cooker. Cook on Low for 8–10 hours or High for 4–5 hours, or until the meat is incredibly tender and shreds easily with a fork.
- Carefully remove the roast and place it on a cutting board. Tent loosely with foil and let it rest for 15 minutes. Remove and discard the herb bundle and bay leaves from the cooking liquid.
- Skim off any excess fat floating on top of the cooking liquid.
- To thicken the gravy, whisk the cornstarch with the cold water to create a slurry. Pour the slurry into the remaining liquid in the slow cooker. Cover and cook on High for 15-20 minutes, stirring occasionally, until the gravy thickens.
- Shred the meat with two forks or slice thickly. Serve immediately spooned generously with the rich gravy and root vegetables.