Yield 10 Number Of Ingredients 17 Steps:
1 For the dough: Use your fingers to knead together the cornstarch and softened butter in a small bowl 2 Whisk together the flour and salt into a large bowl 3 Add the water and vinegar; stir to incorporate 4 Add the butter mixture, using your hands to fold it into the flour mixture, kneading until it is fully incorporated 5 Transfer to a floured work surface and knead for a few more minutes, adding flour to the dough as necessary, until it is elastic and tacky but not sticking to your hands 6 Refrigerate, wrapped in plastic wrap, for at least 30 minutes 7 For the filling, first build a bechamel sauce: Melt 1 tablespoon of the butter in a saucepan over medium heat until foamy, and stir in the flour to form a smooth roux 8 Cook, stirring occasionally, until the roux turns sandy brown in color, about 5 minutes 9 Meanwhile, in a separate saucepan bring the milk just to a boil over medium heat, then turn off the heat 10 Once the roux has browned, whisk in the hot milk; bring the mixture to a boil (medium heat) and cook for 10 minutes, whisking constantly 11 Remove from the heat and let cool 12 Wash and very thoroughly dry the chard, then strip the leaves from the stems 13 Reserve the stems for another use, if desired 14 Stack the leaves and cut them into strips 15 Melt the remaining tablespoon of butter in a large skillet over medium heat 16 Add the scallions and cook until tender, 2 to 3 minutes 17 Add the chard strips; cook until they have completely collapsed and most of the liquid has evaporated, 3 to 4 minutes 18 Add the caramelized onions and Pernod and cook, stirring occasionally, for 3 minutes or until the filling is moist but no longer soupy 19 Add the bechamel; bring the mixture to a boil, then reduce the heat so the mixture is barely bubbling 20 Stir in the cheese until it is emulsified 21 Stir in the salt, taste, then add more salt if needed 22 Cover and refrigerate until cold, at least 1 hour 23 Position oven racks in the upper and lower thirds of the oven; preheat to 450 degrees 24 Line two baking sheets with parchment paper or silicone liners 25 To form the empanadas, transfer the dough to a lightly floured work surface 26 Roll out the dough to a thickness of 1/4 inch 27 Trace and cut out ten 4-inch rounds, gathering the scraps and rerolling the dough as necessary 28 (If the dough rounds shrink, refrigerate them for 30 minutes, then try rolling them again 29 ) Brush a little egg wash around the inside rim of each dough round, and scoop 3 tablespoons of the chilled filling into the center of each round 30 Rub your hands with oil, then pick up each round and fold it into a half-circle, stretching over the filling if needed 31 Pinch 1/2 inch of dough together around the outside, then crimp the edges to seal 32 Arrange the empanadas on the baking sheets, spaced at least 1 inch apart 33 Brush each one with more egg wash 34 Bake on the upper and lower racks until deeply golden brown, rotating the baking sheets top to bottom and front to back halfway through baking, 15 to 20 minutes total 35 Serve hot...