Potato Leek Pie

Ingredients

 * 2 tbsp butter, at room temperature
 * 3 leeks, white and light green parts only, split lengthwise, cut into thin slices and washed well
 * 6 baking potatoes, peeled and cut into thin slices
 * 3 tsp salt
 * ¼ tsp freshly ground black pepper
 * 2 cups heavy cream
 * 1 cup gruyère cheese, grated

Directions

 * 1) Heat the oven to 300°F.
 * 2) Grease a two-quart gratin or shallow baking dish with butter.
 * 3) Spread half of the leeks in the dish and top with half of the potatoes.
 * 4) Sprinkle 1½ tsp of the salt and ⅛ tsp of the pepper.
 * 5) Layer the remaining leeks in the dish and top with the remaining potatoes.
 * 6) Sprinkle the remaining 1½ tsp salt and ⅛ tsp pepper.
 * 7) Pour cream over the potatoes and evenly sprinkle cheese on top.
 * 8) Bake the gratin until the potatoes and leeks are tender and the top is golden brown, for about 1½ hours.
 * 9) If the top has not browned sufficiently, broil for one or two minutes.