¼poundfresh mushrooms, cut into fine cubes (about 1¼cups)
Juice of ½lemon
½ pint shucked oysters with their liquor
⅛teaspoon freshly grated nutmeg
Pinch of cayenne pepper
Freshly ground black pepper to taste
3tablespoons finely chopped parsley
½cup finely grated Gruyère or Swiss cheese
Preheat the oven to 425 degrees.
Trim off the stem end of the eggplant. Cut the eggplant in half lengthwise. Run a sharp paring knife around the inside perimeter of each half, about ½inch from the skin. Do not penetrate the skin. Score the insides of each half with the paring knife, running it to within about ½inch of the bottom skin. The scoring should have a diamond pattern.
Sprinkle the top of each half with salt. Place the halves, cut side up, in a baking dish. Place in the oven and bake for about 20 minutes. Remove and let cool.
Meanwhile, heat 1 tablespoon butter in a saucepan and add the flour, stirring with a wire whisk. Add the milk, stirring rapidly with the whisk. When blended and smooth, remove from the heat.
Heat the remaining 1 tablespoon butter in a saucepan and add the onion and shallots. Cook, stirring, until they are wilted. Add the mushrooms and sprinkle with lemon juice. Cook, stirring, until the mushrooms give up their liquid. Cook until the liquid evaporates.
When the eggplant halves are cool enough to handle, scrape away the inside pulp, leaving a shell for stuffing. Chop the eggplant pulp. Add the pulp to the mushrooms and cook, stirring, over low heat, about 5 minutes.
Drain the oysters and reserve the liquor. There should be 3 to 4tablespoons. Add this to the eggplant-and-mushroom mixture. Cook about 4 minutes. Pour and scrape the white sauce into the eggplant-and-mushroom mixture. Stir in the nutmeg, cayenne, salt, and pepper.
Add the shucked, drained oysters and parsley. Blend. Spoon an equal portion of the filling into each eggplant shell. Arrange the eggplant halves, stuffed side up, in a baking dish. Sprinkle the top of each with an equal portion of the cheese. Place in the oven and bake 25 minutes.
Cut each eggplant half crosswise into serving pieces.