Combine yogurt and flour in a bowl; stir well, and set aside.
Coat a saucepan with cooking spray, and place over medium heat until hot. Add onion and green pepper; cook, stirring constantly, 4 minutes. Add yogurt mixture, broth, and remaining ingredients; stir well. Reduce heat, and cook, uncovered, 20 minutes; stir occasionally. Serve warm with chicken, pork, or Chinese noodles.