Place heavy soup pot on low heat. Add butter. Melt slowly with out browning.
Add the onions, celery and green onions and cook for 10-12 minutes. Add garlic for last minute.
Add fresh basil and crushed pepper flakes.
Add the flour and cook for two minutes to blend.
Add the cream and simmer. The soup base should thicken. Add half and half and continue to simmer for 10 minutes.
Add the liquid from the oysters and simmer.
Add the oysters right before serving and cook for five minutes.
Serve within five minutes of cooking the oysters.
Recipe provided by Regina Charboneau.
Time to prepare: 30 minutes.