Heat the olive oil in a large saucepan over medium heat. Add the onions, celery, and bell pepper and saute for about two minutes. Add the mushrooms and cook until onions are translucent and the celery and bell pepper are softened, about ten minutes.
Add the garlic, parsley, thyme, oregano, basil, and red pepper flakes and cook for about two minutes, stirring frequently. Add balsamic vinegar, tomatoes and beans and bring to a simmer. Simmer uncovered for about 10 minutes, stirring occasionally. Stir in the kale and cook over medium-low heat until wilted and tender, about 15 minutes. Add salt and pepper.
Serve over rice or pasta, or with crusty bread on the side.
Recipe by Baked In at https://www.baked-in.com/2012/03/13/kale-and-white-bean-stew/