- In a medium stockpot, sauté onion, celery, and garlic over medium-low heat in butter until soft—about 3 minutes.
- Add flour and stir until light brown. Add wine and reserved oyster liquor and cook one minute.
- Add remaining ingredients, except the oysters, and reduce heat to low. Cook soup for 10 minutes, stirring occasionally.
- Add oysters and cook for 1 minute. Salt and pepper to taste and serve immediately.