In 5- to 6-quart Dutch oven, heat oil over medium-high heat. Add carrots, celery, garlic, zucchini, onion and green beans; cook 7 minutes, stirring frequently, until crisp-tender. Add both cans of tomatoes, both cans of beans, broth, salt and pepper flakes. Heat to boiling; reduce heat. Simmer uncovered 20 minutes or until vegetables are tender.