Heat olive oil in a Dutch oven over medium-high heat. Add chopped onion and chicken; sauté 5 minutes or until lightly browned. Add zucchini and next 9 ingredients (zucchini through broth); bring to a boil. Cover, reduce heat, and simmer 30 minutes or until vegetables are tender.
Add bell peppers, and cook, uncovered, 10 minutes, stirring occasionally. Sprinkle with cilantro.
Note: Store stew in refrigerator up to 2 days. Reheat in a saucepan over medium heat until thoroughly heated; sprinkle with cilantro before serving.