Heat oil in a small Dutch oven over medium heat. Add onion and celery; cook 7 minutes or until tender, stirring frequently. Stir in garlic; cook 1 minute. Add water, broth, tomatoes, and tomato sauce. Bring to a simmer; cook 25 minutes, stirring occasionally. Stir in pasta; cook 8 minutes. Add spinach; cook 2 minutes or until spinach wilts and pasta is done. Stir in pepper and salt. Divide soup evenly among 4 bowls; top with cheese.