Heat oil in a large Dutch oven over medium-high heat. Add onion, bell pepper, and garlic; sauté 5 minutes or until tender. Add zucchini and next 6 ingredients (zucchini through tomato sauce); bring to a boil. Cover, reduce heat, and simmer 30 minutes. Add kidney beans, green beans, and parsley; simmer, uncovered, 5 minutes or until thoroughly heated. Ladle into 6 bowls; sprinkle with cheese. Garnish with fresh thyme, if desired.