Chop and mince. Begin by dicing the onions, carrots, and celery, and don't forget to mince that aromatic garlic.
Sauté and season. Heat the olive oil in a large, heavy-bottomed pot or Dutch oven over medium heat, then add the onions, carrots, celery, and garlic, sautéing until fragrant, approximately 3 minutes. Season by adding the salt, pepper, and red pepper flakes. Allow the mixture to cook and soften for 8 to 10 minutes.
Mix in the tomatoes. Add the tomatoes to the vegetable mixture and cook for an additional 2 minutes, allowing the flavors to meld.
Create the broth base. Combine the broth, white wine, kale, and cannellini beans into the mixture, optionally placing the Parmesan rind on top, and gently bring the soup to a gentle boil.
Simmer. Reduce the heat to low, cover, and let it simmer gently for 15 minutes before serving with a side of rustic, crusty bread.