Sauté the vegetables: Heat olive oil in a large pot over medium heat. Add onion, carrots, and celery and cook for 5–6 minutes until softened.
Add garlic and herbs: Stir in garlic, oregano, and thyme. Cook for 30 seconds until fragrant.
Build the soup: Add white beans, diced tomatoes, and vegetable broth. Season with salt and black pepper.
Simmer: Bring to a gentle boil, then reduce heat and simmer for 15–20 minutes so the flavors blend.
Add greens: Stir in kale or spinach and cook for 2–3 minutes until wilted. Add lemon juice.
Serve: Serve warm topped with parsley and Parmesan if desired.