1 medium (about 3 to 4 pounds) butternut squash—peeled, seeded and cut into ¼-inch cubes
10 sage leaves, chiffonade
Kosher salt, to taste
½ cup (¼ pound) aged cheddar, cut into ¼-inch cubes
1 egg, for the egg wash
1 tablespoon whole milk, for the egg wash
Directions
In the bowl of a food processor, combine all of the dry ingredients. While the motor is running, add the cubes of butter. Once the butter is incorporated, stream in the water. Transfer the dough mixture to a lightly floured surface and knead into a ball. Cover the dough with plastic wrap and refrigerate for 2 hours.
Meanwhile, make the butternut squash and sage filling: Preheat the oven to 350º. In a small saucepot, brown the butter until it's a deep-brown color, 4 to 5 minutes. On a foil-lined baking sheet, toss the cubed butternut squash with the brown butter and sage, and season with salt. Roast the squash until very tender, 50 to 55 minutes. Allow the squash to cool at room temperature. Then, in a medium bowl, toss the cooled roast squash and cubed cheddar. Set aside for later.
In a small bowl, whisk together the egg and milk, and set aside.
Cut the dough in half. Using a rolling pin, roll one of the halves into a ⅛-inch-thick 36-by-36-inch square. Cut nine 4-by-4-inch squares and repeat the same process with the second ball of dough. Take one 4-by-4-inch square piece and place just less than 1½ tablespoons of the squash and cheese filling in the center. Lightly brush the edges of the dough with the egg wash, place another dough square directly on top and seal the edges while pressing out any excess air. Bake the squares until golden brown, 15 to 20 minutes. Transfer the squares to a platter and serve hot.