Preheat your oven to 375°F (190°C).

Thinly slice the Yukon Gold or Russet potatoes into even rounds, about 1/8 inch thick.

In a saucepan over medium-low heat, combine heavy cream with fresh thyme, salt, and pepper. Warm gently until hot but not boiling.

In a greased baking dish, layer the sliced potatoes, overlapping slightly. Pour some cream over each layer.

Sprinkle grated Parmesan cheese over the top of the potato layers.

Bake for 45-60 minutes until edges are crispy and golden brown.

Let the dish rest for about 10 minutes before serving.