01 - In a large bowl, whisk together flour, granulated sugar, and salt. Cut in cold butter using a pastry cutter or fork until the texture is crumbly. Add ice water one tablespoon at a time, mixing gently until the dough just comes together. Form the dough into a disk, wrap in plastic, and refrigerate for at least 30 minutes.
02 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
03 - In a large bowl, toss sliced pears with light brown sugar, cinnamon, ginger, nutmeg, lemon juice, and cornstarch until evenly coated. Gently fold in chopped pecans.
04 - On a lightly floured surface, roll the chilled dough into a 12-inch circle. Carefully transfer the dough to the prepared baking sheet.
05 - Arrange the pear and pecan mixture in the center of the pastry, leaving a 2-inch border. Fold the edges of the dough over the filling, pleating as needed. Brush pastry edges with beaten egg and, if desired, sprinkle with turbinado sugar.
06 - Bake on the center rack for 35 to 40 minutes, or until the crust is golden brown and the filling is bubbling. Transfer galette to a wire rack and cool for at least 15 minutes before slicing.