# What you need:
→ Potatoes
01 - 2.5 lbs (1.1 kg) Yukon Gold or Russet potatoes, peeled and thinly sliced (about 1/8-inch thick)
→ Dairy
02 - 2 cups (480 ml) heavy cream
03 - 1 cup (240 ml) whole milk
04 - 2 cups (200 g) Gruyere cheese, grated
05 - 1/2 cup (50 g) Parmesan cheese, grated
06 - 2 tbsp (28 g) unsalted butter, plus extra for greasing
→ Aromatics & Seasonings
07 - 2 cloves garlic, minced
08 - 1/2 tsp freshly ground black pepper
09 - 1 1/2 tsp Kosher salt
10 - 1/4 tsp ground nutmeg
11 - 1 tbsp fresh thyme leaves (or 1 tsp dried thyme)
# How to make it:
01 - Preheat your oven to 375°F (190°C). Grease a 9x13-inch (23x33 cm) baking dish with butter.
02 - In a medium saucepan, combine heavy cream, milk, garlic, salt, pepper, and nutmeg. Warm over medium-low heat until just steaming (do not boil). Stir in half the thyme.
03 - Arrange half of the sliced potatoes in an even layer in the prepared baking dish.
04 - Pour half the cream mixture over the potatoes. Sprinkle with half the Gruyere and half the Parmesan.
05 - Layer the remaining potatoes on top. Pour over the rest of the cream. Top with the remaining Gruyere, Parmesan, and thyme. Dot with butter.
06 - Cover tightly with foil and bake for 45 minutes. Remove foil and continue baking for 25-30 minutes, until potatoes are tender and the top is golden and bubbly.
07 - Let rest for at least 15 minutes before serving to allow the sauce to thicken.
