Heat oven to 300 degrees F.
Brown meat well in oil in large ovenproof Dutch oven, 15 minutes.
Add sauce, vinegar, broth, sugar, mustard, Worcestershire, chili powder, onion, garlic and thyme to pot. Bring to boiling.
Bake, covered, in 300 degree F oven 3 to 4 hours, turning meat every hour, until fork-tender. Let stand at least 30 minutes in pan. Remove meat from pot. Skim fat. Slice beef. Serve with sauce on rolls.