6 chicken breasts with the bone, about 3 pounds total
12 cups low-sodium chicken broth
2 cups canned crushed Italian tomatoes
1 large onion, diced
3 carrots, peeled and thinly sliced
3 celery ribs, finely chopped
1 red bell pepper, seeded and diced
8 ounces orzo or other small, shaped pasta
4 cups chopped fresh spinach, escarole or kale
¼ cup chopped fresh parsley
¼ cup chopped fresh oregano
salt to taste
freshly ground black pepper