Heat oven to 160°C (320°F). Pat the chuck roast dry. Season generously with salt & pepper. Lightly dust with flour if using.
In a large oven-safe pot or Dutch oven on high heat, add olive oil. Sear beef 3–4 min per side until deeply browned. Remove and set aside.
Lower heat to medium. Add onion, carrots, celery. Cook 6–8 min until lightly caramelized. Add garlic and tomato paste. Cook 1 minute until fragrant.
Pour in beef stock and Worcestershire sauce. Add herbs and bay leaf. Return beef to the pot (liquid should come about halfway up). Bring to a gentle simmer.
Cover and transfer to oven. Cook around 2 hours, until the beef is fork-tender (periodically check that the sauce doesn't boil away).
Remove herbs and bay leaf. Shred or slice the beef. Spoon vegetables and sauce over the meat. Serve as is, or with mashed potatoes, rice, or bread.
