Heat nonstick Dutch oven over medium-high heat. Add bacon and cook, stirring, until crisp, about 5 minutes; transfer to paper towels to drain.
Add chicken to Dutch oven, in two batches, and cook until lightly browned on all sides, about 5 minutes per batch. Transfer chicken to plate as it is browned.
Reduce heat to medium. Add chopped onion, celery, and garlic to Dutch oven; cook, stirring, until vegetables are lightly browned, about 8 minutes. Stir in tomato paste until smooth. Add mushrooms and frozen onions; cook, stirring, 1 minute. Add broth, wine, potatoes, and carrots; bring to boil, scraping up browned bits from bottom of pot.
Return chicken and bacon to Dutch oven. Reduce heat and simmer, covered, until vegetables are tender and juices run clear when chicken thigh is pierced with a fork, about 25 minutes.
Meanwhile, whisk together flour and water in small bowl until smooth. Stir in about 1/4 cup of hot stew liquid until blended. Add liquid to pot and cook, stirring occasionally, until liquid bubbles and thickens, about 3 minutes. Serve sprinkled with parsley.
Reprinted with permission from Weight Watchers One Pot Cookbook, copyright (c) 2011. Published by Wiley.