disable dropcap
Ingredients
Serves 4- 1 1/2 pounds russet potatoes
- Kosher salt
- 1/4 cup olive oil
- 1 small onion, halved lengthwise and thinly sliced
- Freshly ground pepper to taste
- 1 1/2 cups heavy cream
- 2 teaspoons finely chopped fresh thyme
- 2 teaspoons finely grated Parmigiano-Reggiano cheese
- Slice potatoes as thin as possible using a knife or a mandolin.
- Place potatoes in a large bowl and add 1/2 teaspoon salt, and mix thoroughly. Let rest for 30 minutes, tossing every five minutes.
- Heat the oil in a small skillet over medium heat and add the onion, a pinch of salt, a pinch of pepper, and cook, stirring frequently, until the onion is caramelized and the skillet is dry, about ten minutes.
- Add the cream and bring to a boil.
- Remove from heat and add the thyme.
- Preheat the oven to 325° F.
- Grease an 8-inch square baking dish and set aside.
- Squeeze the potatoes by handfuls to expel as much liquid as possible.
- Transfer the potatoes to a large bowl and add the cream mixture, tossing to completely coat the potatoes.
- Spoon one quarter of the potato mixture into the prepared baking dish, pressing the mixture firmly into the bottom and sides. Sprinkle the potatoes with 1/2 teaspoon of the cheese, and top with more potatoes. Continue alternating for a total of four layers.
- Cover the dish tightly with plastic wrap, then aluminum foil, and bake for 1 1/2 hours, until the gratin is set and the liquid has been absorbed.
- Remove the aluminum foil and plastic wrap, and cook the gratin in the oven uncovered for an additional 30 minutes to caramelize the top. Let rest for 20 to 30 minutes before serving.
