1. In a saucepan over medium-high heat, sauté onion and garlic in butter or margarine until soft.
2. Add broth, white beans, and tomatoes; stir to combine.
3. Bring to a boil; reduce heat, cover, and simmer for about 5 minutes.
4. Add the kale and Italian seasoning. Simmer until kale has softened, 3 to 5 minutes. Serve warm.
5. Refrigerate leftovers within 2 hours.