- I would not recommend making this without a mandoline. This one works great and is very safe to use. This one also works great and, if you use the guard, is also safe.
- Plan ahead: this recipe takes a total of 90 minutes to bake + 30 minutes to prep.
- To make it ahead and reheat, remove the gratin from the oven after it has baked for 60 minutes. Let it cool, cover with foil, then chill. When ready to bake, bake covered for 20 minutes, remove foil, sprinkle with the reserved cheese, and return to the oven for another 20 minutes or until the mixture is evenly golden and bubbling.
- I can’t recommend enough investing in a very large bowl. At Thanksgiving especially, I find myself using this all the time for making double batches of things, namely stuffing.
- The original recipe calls for using 2 cups of heavy cream, but I find it just as tasty when made with 1 cup of heavy cream and 1 cup of stock.
- The original recipe also calls for peeled potatoes, but I don’t think peeling is necessary.
- 3 ounces (about 1 1/3 cups) grated Gruyère or comté cheese
- 2 ounces (about 2/3 cups) grated Parmigiano-Reggiano
- 1 cup heavy cream
- 1 cup chicken stock or vegetable stock
- 2 medium cloves garlic, minced
- 1 tablespoon fresh thyme leaves, roughly chopped
- Kosher salt and black pepper
- 4 to 4½ pounds red potatoes, unpeeled and sliced ⅛-inch thick on a mandoline slicer
- softened butter for greasing
- Adjust the oven rack to the middle position and heat the oven to 400ºF.
- Combine the cheeses in your largest bowl, see notes above. Transfer ⅓ of the cheese mixture (roughly 2/3 cup) to a separate bowl and set aside. Add the cream, stock, garlic, and thyme to the large bowl. Season generously with salt and pepper — I season with 1 tablespoon kosher salt (Diamond Crystal brand), and I do not find it to be too salty but use less if you are worried. Honestly, I think it could use even more salt — it’s a lot of potatoes.
- Add potato slices and toss with your hands until every slice is coated with the cream mixture, making sure to separate any slices that are sticking together to get the cream mixture in between them.
- Grease a 9×13-inch baking dish with the softened butter. Pick up a handful of potatoes, then transfer them to the baking dish with their edges aligned vertically. Continue placing potatoes in the dish, until all the potatoes have been added. The potatoes should be tightly packed. If necessary, slice an additional potato, coat with the cream mixture, and add to the baking dish. Pour the excess cream/cheese mixture evenly over the potatoes.
- Cover the dish tightly with foil and transfer it to the oven. Bake for 30 minutes. Remove foil and continue baking until the top is pale golden brown, about 30 minutes longer. Carefully remove from oven, sprinkle with remaining cheese, and return to oven. Bake until deep golden brown and crisp on top, about 30 minutes longer.
- Remove from oven, let rest for a few minutes, and serve.
- Prep Time: 30 minutes
- Cook Time: 90 minutes
- Category: Side Dish
- Method: Oven
- Cuisine: American
Keywords: red potatoes, Gruyère, parmesan, gratin, hasselback