Heat oil in a soup pot over medium-high heat. Add onion, cook until limp, about three minutes.  

Remove pot from heat and puree soup in a food processor until smooth and creamy.  Add cooking wine; simmer three to four minutes. 

Add water and bring to a boil. Add celery, a sprinkle of basil, and soy or rice milk and return to a boil.

Add chestnuts, cover, and cook over low heat for 20 minutes. Season lightly with sea salt and simmer another 10 minutes.

Serve garnished with parsley sprigs.