Pastry Shells

Scrub the concave bottom halves of the oyster shells well, using scouring powder and a stiff brush on the outside of the shell. (Once scrubbed clean, the shells can be reused indefinitely and can be washed in the dishwasher.)

On a floured surface, roll the puff pastry into a rectangle measuring 14 inches by 20 inches and about ⅛ inch thick. Cut 16 rectangular pieces (cut lengthwise into quarters and then crosswise into quarters) measuring 3½ inches by 5 inches (this is the correct size for oyster shells measuring 2½ inches by 4 inches at their widest points). You will need only 12 pieces; the remaining 4 can be frozen (well wrapped) for future use. Roll each piece so that it is a little under ⅛ inch thick. Use a fork to prick the pastry well all over.

Spray the inside of the oyster shells with nonstick vegetable shortening and press the puff pastry rectangles into the shells, being careful not to puncture the pastry as you near the point of the shell. With a sharp knife or scissors, trim off excess pastry. Place the prepared shells on a baking sheet, using crumbled pieces of foil where needed to prop the shells so that they are level (they must not tilt to the side or the pastry will not rise evenly and the pennies will spill out). Cover with plastic wrap (preferably Saran brand) and chill for at least 1 hour or up to 24 hours.

To bake, preheat the oven to 425°F.

Cut 12 rectangles of foil just slightly larger than the size of the pastry rectangles. Remove the plastic wrap from the pastry-covered shells and prick the pastry again with a fork. Press the foil rectangles into the pastry shells and fill with pennies or other coins (metal pie weights are not heavy enough and will pop out as the pastry rises). Bake for 15 to 20 minutes or until the pastry is set. Remove the foil with the weights and carefully unmold the pastry from the oyster shells. If not enough weights were used and the shells have risen in the centers, push them down gently to form the center impressions. Return the pastry shells, upside down, to the baking sheet and continue baking for about 5 minutes or just until golden and the centers, when turned right side up, appear to be cooked through, with no wet-looking pastry. Cool on a rack. Store in an airtight container at room temperature for up to 3 days.

Poached Oysters

In a heavy medium-size saucepan, combine all the ingredients for the court bouillon and bring it to a boil. Simmer for 2 to 3 minutes, then lower the heat to just below simmering and add the oysters. Poach gently for 2 to 3 minutes or just until the oysters swell. It is important not to overcook them. With a slotted spoon, remove the oysters to a bowl. They can sit at room temperature for about an hour before serving, but cover them once they cool.

Broth Reduction

Raise the heat and bring the poaching liquid to a boil. Boil rapidly until reduced to 2 tablespoons, about 20 to 30 minutes. The liquid will be thickened and slightly sticky. Set aside until ready to make the beurre blanc.

Beurre Blanc

If the court bouillon reduction has cooled, reheat it over the lowest possible heat until almost simmering. Add the 1 tablespoon of cold water, whisking rapidly. Remove the pan entirely from the heat and whisk in the first piece of the butter. Return the pan to the heat for just a few seconds, whisking rapidly. Remove it again and continue whisking until the butter has completely emulsified and no whole pieces remain. Add the next piece of butter, whisking rapidly. Continue in this way until all the butter is incorporated.

Return to the heat for 15 seconds, whisking rapidly. The sauce should be the consistency of heavy cream. Remove it immediately to a small bowl, preferably glass or ceramic, which will hold the heat. The beurre blanc can be held, covered, at room temperature for up to 2 hours or in a thermos for up to 6 hours. It will thicken slightly as it cools. (You will have ⅔ cup sauce.)

Final Assembly

Arrange the pastry shells on oyster or serving plates, using dried seaweed if desired to keep the shells level. If the oysters are large, cut them in half before arranging them in the shells. Spoon a full teaspoon of the sauce over each oyster. If desired, place a small dollop of caviar toward the rounded tip. Pass the extra sauce. (I went whole hog and added lots of caviar in this picture because of New Year’s, but the oysters are just as good without the luxurious caviar overlay.)