Step 1Heat oil in large soup pot over medium heat. Add onion, carrot, celery and garlic and saute until vegetables are soft, 10 minutes.
Step 2Add water, tomato paste, tomatoes and tomato puree. Bring to boil. Reduce heat and simmer 30 minutes. Puree in blender in several batches, if necessary.
Step 3Return soup to pot and add basil and spinach leaves. Cook until tender, 3 to 4 minutes. Add salt and pepper to taste.