Preheat oven to 325°F
Generously salt chuck roast on all sides and dust with flour, cutting into smaller pieces for even braising
Heat Dutch oven over medium heat and sear chuck roast until browned on all sides, then remove and set aside
Add butter and onions to the Dutch oven and sauté until caramelized, about 40 minutes, stirring every 5 minutes
Deglaze the pan with wine and bone broth, then add Worcestershire sauce and Dijon mustard
Add chuck roast back into the pot, season with salt, thyme, and pepper
Cover with lid and braise in the oven for 3-4 hours until meat is falling apart
Serve with mashed potatoes or crusty bread
