1. Heat oil in large pot over medium heat. Cook bratwurst until well browned on all sides, remove and reserve. Once cooled, slice into half-inch pieces. Add onions, garlic, carrots and celery to pot, and season with salt. Cook vegetables, stirring until tender, about 8 minutes.
2. Increase heat to medium-high and add tomatoes and their juice. Cook, stirring, until mixture begins to caramelize- about 3 minutes.
3. Add stock, potatoes and beans, and bring soup to boil. Reduce heat and simmer until potatoes are tender, about 10 minutes; then stir in kale and chopped bratwurst.
4. Cook, covered, until tender, about 2 minutes; then season with salt and pepper. Top with Parmesan.