Heat the oil in a large pot over medium high heat. Once the oil is shimmering, add the onion, garlic, Italian seasoning, and red pepper flakes. Let cook until onions are tender, about 5 minutes.
Add the beans and broth and stir. Using an immersion blender, blend the soup until creamy. Add the potatoes, season with salt and pepper and bring the soup to a boil. Reduce the heat and let the soup simmer for about 30 minutes or until potatoes are tender.
Once potatoes are tender, add the kale to the pot. Simmer the kale until wilted.