Dough: Mix the flour and salt in a medium bowl and make a well in the center. Place the butter, egg and yolk in the well. Rub the mixture between your fingertips until it forms a crumbly mass. Sprinkle with the water and knead in the bowl until it comes together into a dough. (If the dough seems too moist, sprinkle with additional flour, and knead it in briefly.) Divide the dough into 2 thick disks, and wrap each in plastic wrap. Refrigerate until chilled, about 2 hours.;
Filling: In a medium skillet, heat the walnut and olive oils over high heat. Add the pears and cook, stirring occasionally, until lightly browned and beginning to give off their juices, about 2 minutes. Transfer to a medium bowl and cool completely. Stir in the remaining ingredients. Cover and refrigerate until ready to use.
1 large egg beaten with 1 tablespoon water, for glazing
If the dough is too hard to roll easily, let it stand at room temperature to warm slightly. On a lightly floured surface, working with 1 portion of dough at a time, roll into a 1/16-inch thick circle. Using a small saucer as a guide, cut out six 4 1/2-inch rounds. Repeat with the remaining dough. Place equal amounts of the filling on the lower halves of the rounds. Fold over to enclose the filling, then crimp closed with the tines of a fork. Place on a parchment paper-lined (or lightly greased) baking sheet. Cover loosely with plastic wrap and refrigerate for 1 hour.
Preheat the oven to 375 degrees F. Brush the empanadas lightly with the egg mixture. Bake until golden brown, 15 to 20 minutes. Serve warm.