Serves 8
Notes
This is a great dish to make when I am cooking for the whole family or a large group, since it goes in the oven and doesn’t require a lot of prep time or attention while it’s cooking. Onions, potatoes, cream, and cheese come together here, in the ultimate side dish. This gratin is easy to put together; then just slip it into the oven, next to whatever you are roasting, and toss a salad, and your balanced meal is done. Think about this dish when you are having people over for brunch or breakfast. Make it in a large baking pan, cut it into squares, and serve each portion on a dish with a fried or poached egg or two on top.
Ingredients
- 2 tablespoons unsalted butter, plus more for the baking dish
- 2 large sweet onions, thickly sliced
- Kosher salt
- 8 large fresh sage leaves
- 1 cup heavy cream
- 1 cup whole milk
- 2 fresh bay leaves
- 2 pounds medium russet potatoes, peeled, sliced about 1/4 inch thick
- 6 ounces Italian Fontina
- 3/4 freshly grated Grana Padano
Directions
Butter a 9-by-13-inch baking dish, and set it aside. Preheat the oven to 400 degrees.
Melt the 2 tablespoons butter in a medium Dutch oven over medium heat. When the butter is melted, add the onions, season with 1 teaspoon salt, and cook, stirring occasionally, until the onions are wilted, about 10 minutes.
Add the sage leaves, let them sizzle for a minute, then add the cream, milk, and bay leaves. Bring to a simmer, and season with 1 teaspoon salt. Add the potatoes, and simmer just to combine, 3 to 4 minutes.
Add the Fontina and Grana Padano to a medium bowl, and toss to combine them. Transfer half of the potato-and-cream mixture to the baking dish, and spread it in an even layer. Sprinkle with half of the cheese mixture. Repeat with the remaining potatoes, then the cheese. Cover the baking dish with foil, and bake until it’s bubbly and the potatoes
are tender, about 30 minutes. Uncover, and bake until the top is golden brown and crusty and the potatoes have absorbed the cream and are no longer soupy (it will thicken up more as it cools as well), about 30 minutes more. Discard the sage and bay leaves. Let cool for 5 to 10 minutes before serving.
