In a large pot, heat olive oil over medium heat. Add onion, carrots, and celery, and sauté until tender, about 5 minutes.
Stir in garlic and cook for an additional minute.
Pour in the vegetable broth and add the diced tomatoes. Bring to a simmer.
Add green beans, zucchini, peas, oregano, basil, salt, and pepper.
Cook for 10-15 minutes, until vegetables are tender.
If desired, add cooked pasta just before serving.
Garnish with fresh parsley and serve hot.