Add the onion, carrots, celery, and garlic to the slow cooker.
Stir in the cannellini beans, diced tomatoes, vegetable broth, and Italian seasoning.
Cover and cook on low for 6 to 7 hours until the vegetables are soft.
Stir in the chopped kale and cook for 30 more minutes until the kale wilts.
Season with salt and pepper to taste.
Ladle into bowls and top with grated Parmesan cheese before serving.