Heat the olive oil in a large pot, then add the onion, carrots, and celery and cook for about 5 minutes.
Stir in the garlic and Italian seasoning, cooking for another 30 seconds until fragrant.
Add the beans, diced tomatoes, vegetable broth, salt, and black pepper.
Bring the soup to a boil, reduce the heat, and simmer for about 12 minutes.
Mash about 1 cup of the beans against the side of the pot to thicken the broth naturally.
Stir in the chopped kale and continue simmering for 8 to 10 minutes until tender.
Add the lemon juice and parsley, then taste and adjust the seasoning before serving.