Swiss Potato and Cheese Pie

From Bake! By Nick Malgieri
Makes one 9-inch pie, about 10 servings

NOTE that you should start the dough ahead of time and chill it.

4 tablespoons unsalted butter
2 large white onions, about 1 pound, peeled and finely chopped
2 large tart apples (about 1 pound) such as Granny Smith, peeled, halved, cored, and thinly sliced
Salt
Freshly ground black pepper
Freshly grated nutmeg
1 batch Flaky Pastry Dough – divided into 2 pieces, one slightly larger than the other
1 pound Yukon Gold potatoes, boiled until tender, cooled, peeled, and sliced ¼ inch thick
1 pound Goms or other Swiss raclette cheese, rind removed and thinly sliced (I used regular swiss cheese)
egg wash: 1 egg well beaten with a pinch of salt
one 9x2-inch round cake pan, buttered

For the filling, melt the butter on medium heat in a saute pan or Dutch oven with a cover. Add the chopped onion and cook until it starts to sizzle. Lower the heat, cover the pan, and let the onion sweat until very soft, about 20 minutes. Add the sliced apples and continue to cook uncovered until the apples are tender and the water they have exuded has evaporated. Cool slightly and season with salt, pepper, and nutmeg.

When you’re ready to bake the pie, set a rack in the lowest level of the oven and preheat to 375 degrees.

Roll the larger piece of dough on a floured surface and fit it into the pan, letting any excess dough hang over the edge of the pan. Place a layer of half the sliced potatoes into the pan and season sparingly with salt and pepper. Spread half the onion and apple mixture over them, then top with half the cheese slices. Repeat with the remaining potatoes, onion and apple mixture, and cheese.

Trim the excess dough at the rim of the pan to ½ inch and fold it in over the filling.

Roll the remaining dough to a disk the size of the top of the pie and trim evenly. Arrange on the filling so that the trop crust comes right to the edge of the pan and gently press it to the downturned edge of the bottom crust. Brush with the egg wash and trace a lattice pattern with the back of a fork.

Bake the pie until the crust is deep golden and the filling is well heated through, about 45 minutes. Cool briefly on a rack and serve warm or at room temperature.

Storage: Keep at room temperature on the day it is baked. Wrap leftovers tightly in plastic and store at room temperature for up to two days. Reheat at 350 degrees for 15 minutes and cool slightly before serving again.

Flaky Pastry Dough
2 cups all-purpose flour
½ teaspoon salt
1 teaspoon baking powder
12 tablespoons unsalted butter, cold, cut into 12 pieces
2 large eggs

Combine the flour, salt and baking powder in a medium bowl and stir to combine.

Cut each piece of butter into 4 smaller pieces and add the pieces to the bowl. Using both hands, palms upward, reach under the dry ingredients to the bottom of the bowl and lift them up through the contents of the bowl several times to distribute the pieces of butter evenly.

Use your fingertips to pinch the pieces of butter into smaller pieces, alternating that with rubbing the mixture between the palms of your hands, as well as occasionally repeating step 2.

Continue rubbing in the butter until the largest pieces are no more than ¼ inch across, but the whole mixture is still cool and powdery.

Add the eggs and use a fork to break them up. Move the bowl back and forth on the work surface while you stir from the bottom up with the fork until the dough is almost completely mixed.

Invert the dough to a floured work suface and gently press it into a consistent mass.

Divide the dough in half (make one half slightly larger), then flatten each half into a disk. Wrap in plastic and refigerate until firm or as long as 3 days.