Drain soaked cannellini beans and add to crock pot. In a large skillet saute kielbasa rounds until lightly browned. Add to crock pot. In same skillet saute onion, celery and red bell peppers until wilted. Add the tomato paste, garlic and pepper flakes and stir together until mixture is fragrant. Add the mixture to the crock pot along with the chicken broth and water. Stir to combine. Add the bay leave and the other herbs and salt and pepper to taste.
Cook the soup on low for 8 hours. 1/2 hour before soup is done, add the drained diced tomatoes and the kale. Stir into soup. Return lid to crock pot and continue to cook until kale is wilted, about 1/2 hour. In a small skillet melt butter. Add bread crumbs and cook until crumbs are golden brown. Ladle soup into bowls and top with bread crumbs.