Creamy Potato-Leek Gratin

Instructions

1. Preheat oven to 350°F. Grease 13 x 9 glass, ceramic or metal baking dish with 2 teaspoons butter. Trim off and discard ends and dark green outer leaves of leeks. Cut leeks lengthwise in half, then thinly slice crosswise. You should have about 6 cups. Rinse and drain leeks very well to remove any grit.
2. In 5-quart sauce pot, melt remaining 2 tablespoons butter over medium-high heat. Add leeks and 1/2 teaspoon salt; cover and cook 14-16 minutes or until leeks are very soft and start to brown, stirring occasionally. Transfer leeks to bowl. You should have about 2 1/2 cups leeks.
3. While leeks cook, peel and thinly slice potatoes.
4. Into same sauce pot, add cream, cayenne, nutmeg and remaining 2 teaspoons salt; heat to boiling over medium-high heat. Add potatoes and cook 4-5 minutes or until cream becomes very thick, stirring frequently.
5. Transfer half of potato mixture to prepared dish; spread half of leeks evenly on top, then sprinkle with half of cheese. Repeat with remaining potatoes, leeks and cheese. Bake gratin 40 minutes or until potatoes are very tender when knife is inserted in center and top is golden brown. Let stand 10 minutes before serving.