# What You'll Need:
→ Potatoes
01 - 2.5 lbs Yukon Gold or Russet potatoes, peeled and sliced 1/8-inch thick
→ Dairy
02 - 2 cups heavy cream
03 - 1 cup whole milk
04 - 2 cups Gruyere cheese, grated
05 - 1/2 cup Parmesan cheese, grated
06 - 2 tablespoons unsalted butter, plus additional for greasing
→ Aromatics & Seasonings
07 - 2 cloves garlic, minced
08 - 1/2 teaspoon freshly ground black pepper
09 - 1 1/2 teaspoons Kosher salt
10 - 1/4 teaspoon ground nutmeg
11 - 1 tablespoon fresh thyme leaves or 1 teaspoon dried thyme
# Steps:
01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish generously with butter.
02 - Combine heavy cream, whole milk, minced garlic, Kosher salt, ground pepper, and nutmeg in a medium saucepan. Heat gently over medium-low until just steaming, without boiling. Stir in half the thyme.
03 - Place half the sliced potatoes in an even layer in the prepared baking dish.
04 - Pour half of the warmed cream mixture over the potatoes. Sprinkle with half the Gruyere and half the Parmesan cheese.
05 - Arrange the rest of the potatoes atop the first layer. Cover with remaining cream mixture. Add remaining Gruyere, Parmesan, and thyme. Dot with butter.
06 - Cover the dish tightly with foil. Bake for 45 minutes.
07 - Remove foil and bake an additional 25 to 30 minutes, until potatoes are tender and the top is golden and bubbling.
08 - Allow to rest for at least 15 minutes before serving to thicken the sauce.
