Puree tomatoes in the blender with 1/4 cup water. Start to boil the rest of the water in a medium sauce pan. Add purred tomatoes, chopped onion and chopped celery to the water and bring to a boil. Add salt and pepper and let simmer for about 5 minutes.
Tastes really good, and is basically just veggies and water. Fills you up, and if you want you can also add chunks of regular firm tofu to the soup before boiling. YUM!