Pat the chuck roast dry and season all over with fine sea salt and freshly ground black pepper.

In a large Dutch oven or heavy-bottomed ovenproof pot, heat olive oil over medium-high heat until shimmering. Sear the roast on all sides until deeply browned (about 3–4 minutes per side). Transfer the roast to a plate and set aside.

Reduce heat to medium. Add two tablespoons of olive oil to the pot, then add sliced onions and cook, stirring occasionally, until they begin to soften and brown, about 20–30 minutes. Add minced garlic during the last minute of cooking.

Stir in maple syrup or brown sugar to accelerate caramelization, then sprinkle all-purpose flour over the onions and cook for 1–2 minutes to remove raw flour taste.

Pour in red wine to deglaze the pot, scraping up browned bits from the bottom. Let the wine reduce by about half (2–3 minutes).

Return the seared roast to the pot and add beef stock until the roast is mostly submerged. Tuck in sprig of rosemary and bay leaf, adjusting seasoning if needed.

Bring liquid to a gentle simmer on stovetop, then cover and transfer to a preheated oven at 300°F (150°C). Braise until the roast is very tender and pulls apart easily with a fork, about 3 to 3.5 hours.

Remove pot from oven, transfer roast to a cutting board, tent with foil, and let rest 10–15 minutes.

Skim excess fat from braising liquid, and if desired, reduce sauce on stovetop over medium heat until slightly thickened.

Slice or shred the roast and serve with a generous ladle of caramelized onion sauce.

Serve slices or shredded pot roast over creamy mashed potatoes, buttered egg noodles, or chunky polenta. Spoon plenty of caramelized onion gravy over the meat and sides.

Garnish with chopped parsley for color and serve a crisp green salad or roasted root vegetables on the side.