My daughter Katie makes this meal the best. We all look forward to these special sandwiches— a pleasant change from regular roast beef. You can make this recipe with a smaller roast, but use the full amount of sauce and roast for a shorter time.
Heat the oil in a Dutch oven or large pot over medium-high heat and brown the meat well, turning often about 15 minutes. In a bowl combine the barbecue sauce, vinegar, broth, sugar, mustard, Worcestershire sauce, chili powder, onion, garlic, and thyme. Pour over the meat and bring to a boil. Cover tightly with a lid or aluminum foil and roast in the oven for 3 to 4hours. Remove the meat and shred it with a fork. Return the meat to the pot and keep warm.
Butter the hamburger buns, if desired, and broil them until they are barely brown around the edges. Place one slice of Swiss cheese, if using, on the bottom bun and place under the broiler just until the cheese has melted.
