Preheat oven to dg450.
Open the oysters, leaving -them on the half shell and Oysters Rockefeller serves 6 (or more) reserving the oyster liquor.
Pick over spinach and remove any tough stems and blemished leaves. Rince well and put in a saucepan. Cover and cook, stirring, until spinach is wilted. Cook briefly and drain well. Squeeze to remove excess moisture. Blend or put through a food mill. There should be about 2 cups.
Put the scallions, celery, and parsley into the container of an electric blender and blend. There should be about 1 cup finely blended.
Chop the anchovies and garlic together finely.
Heat 4 tablespoons of butter in a skillet and add the scallionand celery mixture. Stir about 1 minute and add the anchovie mixture. Cook, stirring, about 1 minute, and add the spinach. Stir to blend. Heat remaining 4 tablespoons of butter in a saucepan and add theflour. Blend, stirring with a wire whisk, and add oyster liquor, stirring vigorously with the whisk. Stir in the cream. Season with Tobasco to taste. DO NOT ADD SALT. Add the spinach mixture and Pernod. Let cool
Spoon equal portions of the mixture on top of the oysters and smooth over the tops. Sprinkle with Parmesan cheese. Bake about 25 minutes or until piping hot. Note: The same spinach topping is equally as good, (some think better), with clams on the half-shell. (Clams Rockefeller) **