Heat olive oil in a large pot over medium heat.
Add onion and garlic, sauté for 2-3 minutes until fragrant.
Stir in carrots, celery, zucchini, and bell pepper, cooking for another 5 minutes.
Pour in vegetable broth and diced tomatoes, stirring to combine.
Add green beans, salt, pepper, oregano, basil, and paprika.
Bring to a gentle simmer and cook for 20-25 minutes, until vegetables are tender.
Stir in spinach or kale and cooked beans (if using) and cook for another 2 minutes.
Remove from heat, garnish with fresh parsley, and serve warm.