This is an elevated take on potatoes gratin.  My extended family demands this potato side dish at every holiday meal—and it would be a perfect accompaniment at a dinner party.   Just 20 minutes of prep time makes magic.  And you can par bake it ahead of time and pop it in the oven just before serving. Your guests will ooh and aah the entire meal.  Promise.

• 5 lb bag of russet potatoes, peeled and very thinly sliced using a mandolin
• 2 ½ c heavy cream
• ½ lb finely grated Gruyère or Comté cheese
• ¼ lb finely grated Parmigiano-Reggiano cheese
• 2 tbsp fresh thyme leaves, roughly chopped
• 3 minced garlic cloves
• Kosher salt and freshly ground black pepper
• 3 tbsp butter

1. Preheat oven to 400 degrees.
2. Generously butter a baking dish—rectangular if you have one.
3. Combine the cheeses in a large bowl (big enough for all of the sliced potatoes!).
4. Transfer 1/3 of the cheese mixture to a separate small bowl for topping the gratin later.
5. Add the cream, thyme, garlic, and plenty of salt and pepper to cheese mixture in the large bowl.
6. Add potato slices to the large bowl.
7. Toss the potatoes with cream mixture with your hands until every slice is coated. Be sure to separate any slices that are sticking together so that the cream mixture gets in between them.
8. Pick up a handful of potatoes, organize them into a neat stack, and lay them in the buttered baking dish with their edges aligned vertically. (In other words, the potatoes are not laying down like in a traditional scalloped potato dish—they are standing up on their sides.)
9. Continue placing stacks of potatoes in the baking dish, working around the perimeter and into the center until all potatoes have been added. The potatoes should be tightly packed. (If necessary, slice additional potatoes, coat slices with cream mixture, and add to the dish.)
10. Pour the excess cream/cheese mixture evenly over potatoes until it’s about halfway up sides of dish. You may not need all of the remaining cream mixture.
11. Cover the baking dish tightly with foil and transfer it to the middle rack of the oven. Bake for 30 minutes.
12. Remove the foil and continue baking until the top is pale golden brown, about 30 minutes longer.
13. Remove from oven, sprinkle with the remaining cheese, and return to oven.
14. Bake until the potatoes are deep golden brown and crisp on top, about 30 minutes longer.
15. Remove from oven, allow it to rest for a few minutes, and serve.