1. Prepare the Beef:
- Pat the chuck roast dry with paper towels.
- Season generously with salt and pepper.
2. Sear the Roast:
- Heat olive oil in a large Dutch oven over medium-high heat.
- Sear the beef for 4-5 minutes per side, until deeply browned. Remove and set aside.
3. Caramelize the Onions:
- In the same pot, add sliced onions and sprinkle with sugar.
- Cook over medium heat for 15-20 minutes, stirring occasionally, until golden brown.
- Stir in garlic and cook for 1 more minute.
- Deglaze the pot with balsamic vinegar and scrape up any browned bits.
4. Build the Broth:
- Sprinkle flour over the onions and stir for 1 minute to thicken.
- Pour in beef broth, French onion soup, and wine, stirring to combine.
- Add thyme and bay leaves.
5. Slow Cook:
- Return the seared roast to the pot, nestling it into the onion broth.
- Cover and braise at 325°F (163°C) for 3-4 hours, until fork-tender.
(Slow Cooker Option: Cook on LOW for 8-10 hours or HIGH for 5-6 hours.)
6. Add Cheese (Optional):
- For a classic French onion touch, sprinkle Gruyère or Swiss cheese over the roast in the last 10 minutes and let it melt.
7. Serve & Enjoy!
- Remove bay leaves and discard.
- Slice or shred the beef and serve with mashed potatoes, noodles, or crusty bread.
- Garnish with fresh parsley or thyme and enjoy!