Braised Chuck Roast

Name: Braised Chuck Roast
Ingredients: 3 pounds chuck roast; Kosher salt and freshly ground black pepper; 2 tablespoons duck fat; 3 large Spanish onions, chopped; 1 pound carrots, chopped; 6 ribs celery, chopped; 8 cloves garlic, minced; 1 tablespoon fresh thyme; 3 bay leaves; 1 teaspoon rosemary; 2 cups good red wine; 4 cups veal stock; 2 tablespoons tomato paste; 1 1/2 tablespoons butter; 1 1/2 tablespoons all-purpose flour; Mashed potatoes, polenta or roasted vegetables, for serving, optional