1. Heat BBQ according to package directions and keep warm.
2. In stockpot over medium heat, add the oil, celery and onion.
3. Cook, stirring, until onions are tender (about 5 minutes).
4. Add 3 cups water and potatoes.
5. Cook until potatoes are fork tender.
6. Reduce heat and stir in cream of chicken soup.
7. Heat through.
8. Add more water if soup is too thick for your liking. Ladle into bowls and top with BBQ.
9. Garnish with green onion if desired. Serve hot.