Vegetable oil
3 cups milk
1 1/2 teaspoon salt
Large pinch of ground nutmeg
Large pinch of pepper
1 cup plus 2 tablespoons semolina
2 large egg yolks, lightly beaten
1 cup freshly-grated Parmesan cheese
6 tablespoons butter

Line the bottom of a 15 1/2 x 10 1/2-inch baking pan with aluminum foil. Generously oil the foil.

Heat milk, salt, nutmeg and pepper in heavy saucepan over medium-high heat just to simmering. Do not boil; reduce heat to medium-low. Begin whisking or stirring milk briskly and add semolina in thin steady stream, taking care not to let lumps form. Cook, stirring frequently, until thick enough for spoon to stand upright and unsupported in center of mixture, 5 to 10 minutes.

Reduce heat to low; continue cooking, stirring constantly, until very thick, about 5 minutes longer. Remove from heat.

Add egg yolks, 1/4 cup of the cheese and 2 tablespoons of the butter to semolina mixture; stir until butter is melted and mixture is smooth. Transfer mixture to prepared pan. Pat out with spatula to 1/4 inch thickness. Refrigerate uncovered until cold, at least 1 hour.

Heat oven to 425 degrees F. Turn mixture out of pan onto flat surface; peel off foil. Cut gnocchi out of mixture with 2-inch round cutter.

Arrange gnocchi overlapping in 10-inch square shallow flameproof baking dish. Melt remaining 4 tablespoons butter. Drizzle melted butter over gnocchi. Sprinkle with remaining 1/4 cup cheese. Bake until tops of gnocchi are crisp and golden, 20 to 25 minutes. Place under broiler about 4 inches from heat, until light brown, 1 to 2 minutes. Serve at once.