Potato and Leek Frittata

In a steamer set over boiling water steam the potatoes, covered, for 20 to 25 minutes, or until they are tender, and let them cool until they can be handled.

Peel the potatoes and cut them crosswise into thin slices. In a 12-inch non-stick skillet cook the leek in the butter over moderately low heat, stirring, for 12 to 15 minutes, or until it is very soft, and add salt and pepper to taste.

In a large bowl whisk together the eggs, add 1/2 cup of the Parmesan, 1/2 cup of the Gruyere, the chives, the parsley, and salt and pepper to taste, and whisk the mixture until it is combined well. Stir in the leek and the potatoes.

In the skillet, cleaned, heat the oil over moderate heat until it is hot but not smoking, pour in the egg mixture, distributing the potatoes evenly, and cook the frittata, without stirring, for 14 to 16 minutes, or until the edge is set but the center is still soft. Sprinkle the remaining 1/2 cup Parmesan and the remaining 1/2 cup Gruyere over the top.

If the skillet handle is plastic, wrap it in a double thickness of foil. Broil the frittata under a preheated broiler about 4 inches from the heat for 4 to 5 minutes, run a thin knife around the edge, and slide the frittata onto a serving plate. Cut the frittata into wedges and serve it warm or at room temperature.