Spinach Gnocchi Gratin

In a large heavy saucepan cook the spinach in the water clinging to the leaves, covered, over moderate heat, stirring once or twice, for 3 to 4 minutes, or until it is wilted, refresh it under cold water, and drain it well in a colander.
Squeeze the spinach dry by handfuls and chop it fine.
In a heavy saucepan bring the water and the milk just to a boil with the butter, stirring until the butter is melted, add the flour all at once, and stir the mixture briskly with a wooden spatula until it pulls away from the side of the pan and forms a ball.
Cook the dough over moderate heat, stirring, for 1 minute.
Transfer the dough to a bowl and with an electric mixer beat in the eggs, 1 at a time, beating well after each addition, the salt, the pepper, the nutmeg, and the spinach.
Preheat the oven to 425F.
Into a kettle of boiling salted water drop walnut-size spoonfuls of the paste, about 10 at a time, and simmer them, uncovered, for 5 minutes, or until they rise to the surface and are cooked through.
Transfer the gnocchi as they are cooked with a slotted spoon to a large colander and let them drain well.
Arrange the gnocchi in one layer in a buttered 1 1/2- to 2-quart shallow grating dish or flame-proof baking dish, drizzle the cream over them, and sprinkle them with the Parmesan and salt and pepper to taste.
Bake the gnocchi in the middle of the oven for 10 minutes and broil them under a hot broiler about 4 inches from the heat for 1 minute, or until they are browned lightly.