In a large Dutch oven, heat the olive oil over medium-high heat. Season the beef chuck roast with salt and pepper, then sear it in the pot until browned on all sides, about 4-5 minutes per side. Remove the roast and set aside.
In the same pot, add the sliced onions and a pinch of salt. Cook the onions, stirring frequently, until they are caramelized and golden brown, about 15-20 minutes. Add the minced garlic and cook for an additional 1-2 minutes until fragrant.
Pour in the beef broth and balsamic vinegar, scraping up any browned bits from the bottom of the pot. Stir in the thyme and bay leaves.
Return the roast to the pot, making sure it’s submerged in the liquid and onions. Cover with a lid and transfer to the preheated oven.
Roast for 3 to 4 hours, or until the meat is fork-tender. Check periodically and add more broth if necessary.
Once cooked, remove the roast from the pot and let it rest for 10-15 minutes before slicing.
While the roast rests, set the pot with the onion broth on a stovetop and bring to a gentle simmer.
To serve, slice the pot roast and place it on a serving platter, pour the onion broth over the meat, and sprinkle lightly with shredded Gruyère cheese. Place the platter under the broiler for a few minutes until the cheese is melted and bubbly.
Garnish with fresh parsley before serving.
Notes
Serve the pot roast on a rustic wooden board with a side of creamy mashed potatoes and a sprinkle of fresh thyme for a homey touch.