P&J's Oysters Rockefeller By Al Sunseri, from The P&J Oyster Cookbook, by Kit Wohl and the Sunseri Family
P&J oysters were present at the creation of many legendary dishes of New Orleans' Creole cuisine. One such is the most famous oyster dish of them all – Oysters Rockefeller, invented in the 1880s at Antoine's by the restaurant's proprietor, Jules Alciatore. Al Sunseri has his own way with Oysters Rockefeller. While his grandfather Alfred was a close friend of the Alciatore family, the secret recipe was never divulged.
Note: The most practical approach to preparing oysters on the half-shell, whether they're to be served cold or hot, is to assemble a "tray" in advance that can be used to cook them or serve them – or both. Spread a 3/4-inch bed of rock salt evenly onto a large rimmed platter or baking pan. Firmly set the shells into the salt. This not only stabilizes the shells so that they won't tip, but the salt also helps retain both heat and cold. Cover the tray with plastic wrap and store at room temperature; or, if the oysters are to be served cold, chill the tray in the refrigerator before serving.
Prepare a sufficient number of half-shell trays to hold 48 oyster bottom shells, as described above, using oven-proof baking pans or rimmed baking sheets. Set aside.
Strain the oysters over a bowl to remove grit and to separate them from the liquor. Set the oysters and the liquor aside.
Preheat the oven to 350°F (175°C).
Squeeze as much water as possible from the thawed spinach and chop it finely.
In a food processor, pulse the green onions, celery, and lettuce until finely chopped.
In a large saucepan, heat the butter over medium-low heat. Add and sauté the chopped vegetables and spinach for about 10 minutes, stirring. Stir in the cheese and bread crumbs. (The mixture will be very thick.)
In a separate saucepan, poach the oysters in their liquor over medium-low heat until their edges just begin to curl, 3 to 4 minutes. With a slotted spoon, transfer the oysters from the saucepan to a bowl and discard the poaching liquid.
Place one oyster on each of the bottom shells on the prepared half-shell tray(s) and cover each with a spoonful of the sauce. Bake until the oysters are bubbly and the topping begins to brown, about 10 minutes. Remove the oysters from the oven and sprinkle a dash of Herbsaint and a few drops of lemon juice on top of each. Serve immediately.