Truffled Potato Gratin

Ingredients

• 4 cups whipping cream
• divided
• 2 tablespoons chopped fresh thyme
• 15 whole black peppercorns
• 5 large garlic cloves
• crushed
• divided
• 5 pounds long slender russet potatoes
• peeled
• cut into 1/8-inch-thick slices
• 3 fresh black truffles or three 1/3-ounce jars whole black truffles
• sliced paper-thin

Instructions

1. Combine 2 cups cream, chopped thyme, black peppercorns, and 3 garlic cloves in heavy medium saucepan.
2. Bring to simmer over medium heat.
3. Cover, reduce heat to medium-low, and simmer 15 minutes.
4. Add remaining 2 garlic cloves.
5. Cover; simmer 5 minutes.
6. Strain cream into bowl.
7. Preheat oven to 400F.
8. Butter 13x9x2-inch glass baking dish.
9. Arrange 1/4 of potatoes in even layer in dish.
10. Sprinkle with salt and pepper.
11. Scatter 1/4 of truffle slices over.
12. Spoon 1/4 of cream over.
13. Repeat 3 more times, sprinkling any truffle liquid from jars over potato layers.
14. Pour 2 cups cream over.
15. Press potatoes firmly to compact.
16. Cover dish with foil.
17. Bake gratin 1 hour.
18. Uncover and bake until top is brown, potatoes are tender, and cream bubbles thickly, about 20 minutes longer.
19. Let stand 10 minutes before serving.