Eggplant Parmesan Hand Pies

0 Position a rack in the center of the oven and preheat to 350ºF.
1 If the eggplant is the long and slender variety, trim it and slice into generous 1/2-inch thick rounds. For the globe varieties, cut the eggplant into 1- or 2-inch chunks. Place the eggplant on a rimmed baking sheet and drizzle with the olive oil and salt, tossing to coat. Spread the eggplant slices in a single layer and roast in the oven until golden and very tender, 40-50 minutes, flipping the slices about 30 minutes into the baking time. Remove from the oven and let cool.
2 Increase the oven temperature to 400ºF.
3 Meanwhile, divide the chilled pie dough into 6 portions; work with 1 portion at a time and keep the rest chilled. On a surface dusted lightly with oat flour, roll out each portion into a round that is roughly 1/8" thick. Trim each portion into a smooth, even round, and stack them on a plate. Cover and chill until firm, at least 30 minutes and up to 1 day.
4 Lay the dough rounds on a rimmed baking sheet lined with parchment for easy clean-up. Have the ingredients prepared and standing by.
5 Place a couple of mozzarella slices on a dough round. Top with some parmesan shavings, roasted eggplant slices, cherry tomatoes, olives, basil leaves, and a sprinkle of salt and pepper. Fold up the edges of the dough to make a crust, leaving a couple of inches open in the center. Repeat with the remaining dough rounds; you may not need all of the filling ingredients. (If you have extras, they are perfect piled on toast or tossed into pasta.) If the dough has softened, chill the pies again until firm, 30 more minutes.
6 Beat the egg in a small bowl until lightened in color and foamy. Use a pastry brush to brush the edges of the dough, then sprinkle with a bit of cracked black pepper.
7 Bake the pies at 400ºF until the crusts are golden and crisp, 25-35 minutes, rotating the pan halfway through for even baking. Remove from the oven and let cool slightly. Top with some fresh basil leaves and serve warm or at room temperature.
8 Extra pies keep well refrigerated airtight for up to 2 days and can be reheated in a 350ºF oven or in a skillet set over a low flame.