Preheat oven to 325°F
Generously salt chuck roast on all sides
Heat a Dutch oven over medium heat and add butter and onions
Sauté onions until caramelized (about 30 minutes, stirring every 5 minutes)
Remove caramelized onions from the pot and sear chuck roast about 5 minutes per side
Deglaze the pan with wine and bone broth
Add onions back, add more salt, thyme, and pepper
Add the lid and braise in the oven for 3-4 hours until the meat is falling apart
Serve with mashed potatoes or baguette and top with Gruyère cheese and fresh pepper
