Heat oil in medium Dutch oven over medium heat. Add onion and garlic; cook, stirring, until onion is softened, about 5 minutes. Reduce heat to medium. Add all remaining ingredients except mushrooms and thyme leaves to Dutch oven; bring to boil. Reduce heat and simmer, covered, 1 hour. Add mushrooms to pot and simmer, covered, until meat is fork-tender, about 1 hour longer. Remove and discard thyme sprigs. Serve sprinkled with thyme leaves.
Reprinted with permission from Weight Watchers One Pot Cookbook, copyright (c) 2011. Published by Wiley.