In a large pot, heat olive oil over medium heat. Add chopped onion and garlic. Sauté for about 2-3 minutes until fragrant.
Add carrots and celery. Cook for another 5 minutes, stirring occasionally.
Stir in zucchini, green beans, kidney beans, cannellini beans, diced tomatoes (with juice), and vegetable broth.
Add dried basil, oregano, salt, and black pepper. Stir well.
Bring the soup to a boil, then reduce heat to low. Cover and simmer for 20-25 minutes, until vegetables are tender.
If using spinach, stir it in during the last 2 minutes of cooking, just until wilted.
Taste and adjust seasoning as needed. Serve warm with crackers or crusty bread.
Prep Time: 15 minutes | Cooking Time: 25 minutes | Total Time: 40 minutes
Kcal: Approx. 230 per serving | Servings: 6