Step 1

Prepare Pie Dough: Combine the flour and salt in the bowl of a large food processor. Pulse several times to mix thoroughly.

Step 2

Add the butter and pulse several times until the butter is thoroughly incorporated and the texture resembles that of a coarse meal—you want the butter pieces to be in varying sizes, some small and others slightly larger. This will result in a flakier texture.

Step 3

While pulsing, slowly add the water - you may not need all of it or you may need a touch more - and continue to pulse until the dough just begins to clump together loosely.

Step 4

Remove the dough to a clean counter top, shape together with your hands into a square disc, and cover tightly in plastic wrap. Refrigerate the dough for 1½ to 2 hours. The dough can also be prepped in advance, wrapped tightly in plastic wrap, and refrigerated for 1-2 days.

Step 5

Filling: Preheat the oven to 425°F (220°C) with a rack in the center position. Combine the cubed  butternut squash and diced red onion on a half sheet pan and toss with the extra virgin olive oil, and season with salt and pepper. Spread out evenly onto the baking sheet.

Step 6

Roast the vegetables for 20 to 28 minutes, tossing with a wooden spoon every halfway, or until the vegetables have softened and have begun to caramelize. Set onto a rack to cool completely.

Step 7

Assembly: Reduce the oven to 375°F (190°C). Set aside the egg wash and a pastry brush. Line two half sheet pans with parchment paper.

Step 8

Remove the pie dough from the fridge, and allow it to rest at room temperature for 5 to 10 minutes. Once it has rested, place the dough on a lightly floured counter top.

Step 9

Using a lightly floured rolling pin, roll the dough into a square that is slightly larger than 12 x 12-inches (don’t worry if the edges are not perfectly straight). Using a pastry cutter or knife, trim off the rough edges. Using a pastry cutter, cut the dough into 12 (3 x 4-inch) rectangles. Note: The easiest way to do this is to use a ruler to notch one side of the square of dough at 4-inch intervals and the perpendicular side of the square at 3-inch intervals). Use the ruler to line up the notches and cut the dough into 12 rectangles.

Step 10

Place six of the pie dough rectangles onto the lined sheet pan. Place the remaining six pie dough pieces on a separate parchment-paper lined sheet pan sheet and chill in the refrigerator while you work. Using a spoon, portion the butternut squash onion filling into the center of each rectangle, pressing down slightly to compact the filling into a mound, leaving a ½-inch border on all sides. Sprinkle the tops of the squash and onion with crumbled feta, dividing the cheese evenly among the pies.

Step 11

Using a pastry brush, brush the border lightly with the egg wash. Remove the remaining dough rectangles from the fridge. Using the lightly floured rolling pin, roll each top rectangle dough until they are slightly larger than the bottom rectangles of dough (this will help cover the filling). Place each rectangle on top of the filling-top rectangles. Use a fork to crimp the borders of the dough and seal the pies (dip the fork in flour to prevent it from sticking). Brush the tops of the pies lightly with the egg wash, then use a sharp knife to make two ½-inch slits into the tops of each pie. Chill the filled hand pies in the refrigerator for 10 minutes.

Step 12

Bake for 25 to 30 minutes, or until golden brown. Place the pies on a cooling rack until cool enough to handle. Serve warm from the oven.