1. Put water and bouillon in large pot and bring to a boil.
2. Add potatoes and carrots and simmer for 5 minutes.
3. Add remaining ingredients, except for tomatoes, and continue cooking for 15 minutes over medium heat.
4. Remove 4 chunks of squash and puree in blender.
5. Return pureed mixture to pot and let cook for 10 minutes more.
6. Add tomatoes and cook for another 5 minutes.
7. Remove from heat and let sit for 10 minutes to allow stew to thicken.