4 1/2 dozen freshly shucked oysters, liquor reserved
2 to 2 1/2 c. clam juice, mussel juice or fish stock
1 1/2 tbsp. unsalted butter
1 1/2 tbsp. extra virgin olive oil
2 leeks (white and tender green), thinly sliced
3 garlic cloves, minced
1 1/2 lb. fresh spinach, stems removed
3 c. heavy cream
1 tsp. salt or to taste
1 1/2 tsp. freshly ground pepper

Put the oysters and their liquor in a large pot and "wash" them in their liquor. Lift out the oysters and, if they are very large, cut in half with scissors. Put the oysters in a bowl. Strain and measure the oyster liquor. Add enough clam juice to equal 3 cups of liquid, then add 3 cups of water; set the stock aside.

In a large saucepan, melt the butter in the olive oil over moderately high heat. Add the leeks and saute until softened, about 2 minutes. Add the garlic and cook, stirring, for 30 seconds. Stir in the reserved 6 cups stock and bring to a boil. Remove from the heat and set aside for up to 2 hours. The recipe can be prepared to this point up to 8 hours in advance. Cover and refrigerate.

At serving time, bring the stock to a boil over high heat. Add the spinach, return to a boil and boil for 1 minute. Add the cream, salt and pepper and return to a boil. Add the oysters and bring just to a simmer. Ladle into soup plates and serve immediately. Makes 12 servings.