In a Dutch oven over medium-high heat, add the oysters with their liquor.
Add a bouquet garni consisting of fresh thyme, sage and bay leaves.
Bring this to a boil for 1 minute, then reduce the heat to a slight simmer for about 2 minutes. The oysters will start to curl.
Remove the oysters with a slotted spoon and set aside. Make sure to capture any liquor that comes off the oysters.
Continue to simmer the oyster liquor and herbs for another 5 minutes.
Remove from the heat and set aside.
For the soup base
Melt the butter in a dutch oven over medium-high heat.
Add the green onions, celery, and leeks.
Stir well and saute for about 3 minutes.
Add the garlic and creole seasoning, mix well.
Saute for about 2 more minutes until aromatic.
Add the flour and stir constantly to make a light roux, about 3 minutes.
Add the parsley and stir to completely combine all the ingredients.
Warm the milk, then add it gradually into the roux mixture. Make sure there are no lumps.
Gradually add the heavy cream to the cream base. Make sure a smooth sauce forms with no lumps.
Increase heat and simmer for about 3 minutes, stirring or whisking constantly.
Add 3 cups of oyster liquid (add water to make 3 cups if you don’t have enough).
Bring it to a boil, then lower the heat to maintain a heavy simmer for about 15 minutes, uncovered, while the soup thickens.
Add oysters and serve
Add the oysters plus any liquid that has accumulated with them and continue to simmer for 5 minutes.
Season with kosher salt, black pepper and Tabasco hot sauce.
Serve immediately.
Notes
For detailed background and technique with FAQs, tips, and step-by-step photos, see the full Oyster Soup article.Nutritional values are estimated using a 1-cup serving. Serve as a main course or appetizer.Use the oyster liquor that comes with the oysters; if needed, add cold water to reach 3 cups total.Whole milk provides the best flavor and texture. You may substitute 2% milk, but avoid fat-free milk. Warm the milk before adding it to the roux to prevent lumps.Clean leeks thoroughly before use. Trim the white portion, remove tough outer layers, slice into rings, and rinse in cold water to remove grit. Drain well.Oyster soup is best served immediately. Leftovers can be refrigerated for 3–4 days. Freezing is possible for up to 3 months, but not ideal, as dairy may separate and oysters can lose texture.If reheating causes separation, remove the oysters, whisk the soup with a little water or butter until smooth, then return the oysters and warm gently.