In a 6 qt (or larger) pot, brown both meats together. Drain all but 1 T of the fat from the pot. Add onion, carrot, celery and garlic to the pot, sauté until the onion is translucent and vegetables have softened. Add tomatoes, beans,  stock, and oregano to the pot; season with salt and pepper. Simmer for at least twenty minutes (soup should reduce by about 1/3) to let the flavors come together. Serve with parsley and parmesan.