This is the pie I made a couple of days ago and comes from hotsoursaltysweet.com. The only change I would make is to mix a little flour in with the apples if they're quite juicy; we ended up with lots and lots of juice. You could also leave the butter out of the filling and mix the sugar with the apples too. The pie browned too quickly for me, so I covered it with foil to let the apples finish cooking.
(I also made the Beirut Tahini Swirls yesterday; they were excellent. The recipe is posted on the internet if you want to try them.)
Makes one double-crust eight-inch apple pie with a thick tender potato crust; serves 6 to 8
1 pound potatoes, peeled
About 1 ounce (1 heaping tablespoon) butter
About 1 cup all-purpose flour, plus extra for surfaces
1/4 teaspoon salt
1/4 teaspoon powdered ginger
1 tablespoon sugar
2 large or 3 medium-sized firm apples, peeled and thinly sliced
About 1 ½ ounces chilled butter, in four thin slices
Scant ½ cup sugar
Preheat the oven to 400 degrees. Cut up the potatoes, bring to a boil in water and cook until tender. Drain, add the 1 ounce butter and immediately mash while hot, adding the salt, ginger, and 1 tablespoon sugar. When potatoes are smooth, add ½ cup flour and stir. Add another scant ½ cup flour and stir and knead in, then turn dough out onto a lightly floured surface and knead until smooth, several minutes. Cut in half and roll each half out to a round about 9 inches in diameter [I just used my fingers]. Lightly grease an 8-inch pie plate and line with half the dough. Place on the shell the chopped apples, mounded up in the middle. Drape the other rolled-out pastry sheet over the mounded apples and press the edges together firmly to seal. Make an X-shaped cut, each arm of which should be about 2 inches long, over the central mound of the pie. Bake it in the center of the preheated oven at 400 degrees.
After 45 minutes, the pie should be touched with golden brown. Cut four thin slices from the end of a pound of very cold butter. Lift the pie from the oven and quickly slip a slice of cold butter under each flap of the cut top of the pie. Sprinkle onto each slice of butter about 2 tablespoons sugar (under each flap). Place the pie back in the oven to bake for another 5 minutes. It will be golden brown all over. Take out, let stand five minutes, and serve, hot or warm.