Cut squash in half, remove seeds and stringy center, season with salt and pepper and bake, cut side down, in a pan filled with about an inch of water. It is done when it separates into strands but is not mushy. (See related links below for more information about, and other methods for, cooking spaghetti squash.)

When cool enough to handle, comb out the long strands of flesh with a fork. Place in a heatproof dish, mix with 4 tablespoons of butter, season, cover and reheat in the oven before serving.

Remove the oysters from the shells and pat dry. Combine cream, remaining butter and nutmeg in a heavy saucepan and boil over medium heat until the sauce is reduced to about 1 cup. Remove from heat and whisk in the cheese until it melts.

Stir in the fresh herbs and oysters and cook over low heat until the edge of the oysters start to curl. Season to taste. Arrange the hot squash on a serving platter, pour the sauce over it and serve immediately.