Ingredients

　　2 1/2 pounds russet (baking) potatoes

　　1 1/2 cups thinly sliced well-washed white and pale green part of leek

　　3/4 cup finely chopped onion

　　2 garlic cloves, minced

　　3 tablespoons unsalted butter

　　2/3 cup milk

　　1 1/2 cups crumbled mild goat cheese such as Montrachet (about 6 ounces)

　　1/4 cup minced fresh chives

　　In a saucepan combine the potatoes, peeled and cut into 1-inch pieces, with enough cold water to cover them by 1 inch and simmer them for 10 to 15 minutes, or until they are tender. While the potatoes are cooking, in a heavy skillet cook the leek, the onion, and the garlic in 2 tablespoons of the butter, covered, over moderate heat, stirring occasionally, for 10 minutes, or until the vegetables are soft. Drain the potatoes, return them to the pan, and steam them over moderate heat, shaking the pan, for 30 seconds, or until any excess liquid is evaporated. Force the potatoes through a ricer or the medium disk of a food mill into a bowl and stir in the milk, the remaining 1 tablespoon butter, the leek mixture, half the goat cheese, the chives, and salt and pepper to taste. Spoon the mixture into a buttered 2-quart baking dish, sprinkle the remaining goat cheese over the top, and bake the mixture in the middle of a preheated 350°F. oven for 20 minutes.