Sauté the aromatics: Heat the olive oil in a large pot over medium heat. Add the onion, carrots, and celery.
Cook, stirring occasionally, until softened, about 5–6 minutes. Add the garlic and cook 30 seconds more, until fragrant.
Add core vegetables: Stir in the bell pepper, zucchini, green beans, and potato. Season with a big pinch of salt and pepper.
Cook 2–3 minutes to lightly soften and build flavor.
Build the broth: Add the diced tomatoes with their juices, vegetable broth, beans, Italian seasoning, bay leaf, and smoked paprika if using. Stir to combine and bring to a gentle boil.
Simmer: Reduce to a steady simmer and cook uncovered for 18–22 minutes, or until the potatoes and green beans are tender. Taste and adjust salt and pepper as needed.
Finish with greens: Stir in the kale or spinach and simmer 2–3 minutes, just until wilted and vibrant.
Remove the bay leaf.
Serve: Ladle into bowls and top with fresh parsley or basil. Squeeze a little lemon over each bowl for brightness, if you like.