Makes: 6-8 Servings

    INGREDIENTS:

• 3 pounds russet (Idaho) potatoes 
• 2 tablespoons unsalted butter, softened 
• 1 medium garlic clove, crushed 
• 1 ½ to 2 cups half and half or whole milk
• Kosher salt and freshly ground pepper to taste
• Freshly grated nutmeg to taste
• 4 tablespoons crème fraîche
• ⅓ to ½ cup heavy cream
• ¼ cup Parmesan cheese

   INSTRUCTIONS:

1. Peel and wash the potatoes and slice them into rounds ⅛-inch thick, using a mandoline or a sharp knife. 
2. Butter a 9x12 heavy shallow baking dish, preferably earthenware or cast-enamel, or an oval gratin dish of comparable size. (You could also use a 12-inch cast iron skillet.) Rub the dish with half of the crushed garlic. 
3. In a small saucepan, bring the half-and-half (or whole milk) to a simmer with the remaining garlic and season with salt and pepper. Set aside. 
4. Preheat the oven to 350 degrees F. Arrange the potatoes in one overlapping layer on the bottom of the dish. Season the layer with salt, pepper, and nutmeg. Arrange two more layers on top, seasoning each layer. Press the layers down and compact them. Pour in enough half-and-half to come up just a little below the top layer of potatoes. Set the baking dish on a larger baking sheet, cover with foil, and bake until the potatoes feel tender when pierced with a knife, about 1 hour. 
5. Raise the oven temperature to 425 degrees F, remove the foil, and bake until the top begins to brown, about 10 minutes. Pour just enough cream to cover the top, dab it with crème fraîche and sprinkle evenly with Parmesan cheese. Bake until the top is brown and bubbly, 15-20 minutes more. Remove from the oven and let the potatoes sit for 10 minutes to absorb the cream.

Original Source: Epicurious.com