Season & Sear: Preheat oven to 325°F (165°C). Pat chuck roast completely dry with paper towels and season generously on all sides with kosher salt and black pepper. Heat olive oil in a large Dutch oven over medium-high heat. Sear roast for 4 to 5 minutes per side until a deep mahogany caramelized crust develops. Transfer meat to a platter.

Sauté Aromatics: Reduce heat to medium. Add onion wedges to the pot drippings and cook for 3 minutes until lightly browned. Stir in tomato paste and smashed garlic cloves, cooking for 1 minute until fragrant and darkened in color.

Deglaze & Simmer: Pour in beef bone broth, Worcestershire sauce, and balsamic vinegar, using a wooden spoon to scrape up all the flavorful browned bits (fond) stuck to the bottom of the pot. Return the seared chuck roast and accumulated juices to the pot, nestling herb sprigs and bay leaves around the meat.

Slow Braise: Bring liquid to a gentle simmer, cover tightly with the heavy lid, and transfer to the oven. Braise for 2 hours at 325°F.

Add Carrots: Carefully remove Dutch oven from oven. Scatter peeled carrot chunks around the roast, submerging them partially into the braising liquid. Cover and return to oven for another 45 to 60 minutes until beef shreds effortlessly with a fork and carrots are fork-tender.

Finish Gravy: Transfer beef and carrots to a warm serving platter and tent with foil. Skim excess surface fat from braising broth. Place Dutch oven on stovetop over medium heat. Whisk in cornstarch slurry and simmer for 3 minutes until sauce thickens into a glossy, velvety gravy. Ladle over roast and serve garnished with chopped parsley.