In a large pot, combine the chicken broth, potatoes, onions, carrots and celery. Bring to a boil, reduce heat to medium high and simmer until the potatoes are tender, about 30 minutes

Add the zucchini, tomato sauce, garlic, parsley and cilantro. Reduce heat to medium low and cook for 10-15 minutes or until the zucchini is just tender. Season to taste with black pepper