Make -ahead Swiss Potato Gratin

My family loves scalloped potatoes but this recipe is one that you can make ahead and save a working mom some time.I found this recipe in woman's world 3/1/05

• Ready In: 2 hrs 40 mins
• Serves: 8

Ingredients

• 3  lbs yukon gold potatoes, peeled, thinly sliced (8 cups)
• 2  tablespoons butter or 2  tablespoons margarine
• 2  leeks, white and light green parts only, sliced
• 3  cups half-and-half cream
• 1⁄2 cup all-purpose flour
• 1⁄3 cup  grated parmesan cheese
• 1  teaspoon salt
• 1⁄8 teaspoon cayenne pepper
• 1⁄8 teaspoon ground nutmeg
• 1  cup  shredded swiss cheese

Directions

1. Line 2 baking sheets with paper towels. In a pot combine potatoes with enough water to cover. Bring to a boil; Drain.
2. Arrange on baking sheets.
3. In a skillet over medium-high heat melt butter and add leeks.Cook until softened, 3 minutes.
4. Whisk together next 6 ingredients in shallow 2 1/2 quart baking dish layer half of potatoes, half of leeks and 1/2 cup swiss cheese.
5. Pour 1 1/2 cups half and half cream mixture over cheese.
6. Repeat layering, reserving remaining Swiss cheese.
7. Cover and refrigerate.
8. Remove from refrigerator 1 1/2 hrs before baking.
9. Preheat oven to 375 degrees.
10. Bake covered until bubbly, 1 hour,15 minutes.
11. Preheat Broiler.
12. Uncover casserole; sprinkle with remaining swiss cheese.
13. Broil until just browned, 3 minutes.
14. MAKE IT IMMEDIATELY! AND SKIP REFRIDERATING THE CASSEROLE AND REDUCE BAKING TIME BY 30 MINUTES.