Directions

1. Line a baking sheet with parchment paper or a nonstick baking mat.
2. Sprinkle work surface with flour. Roll out dough to a 14-inch round, about 1/4-inch thick. Transfer dough to prepared baking sheet and refrigerate until ready to use, up to 1 hour.
3. In a small bowl, mix together cornstarch, sugar and salt. In a large bowl gently toss together pears and cornstarch mixture until evenly coated. Mound pear mixture on top of dough, leaving a 4-inch border all the way around. Fold dough over pear mixture, overlapping where necessary and gently pressing to adhere the folds. Transfer galette to refrigerator and let chill, 20 to 30 minutes
4. Meanwhile, preheat oven to 400 degrees. In a small bowl, beat egg. Brush edges of dough with egg, and sprinkle edges with sanding sugar. Dot top of galette with butter. Transfer to oven and bake until crust is golden brown and juices are bubbling, about 1 hour.
5. Meanwhile, place apricot jam in a small saucepan over medium heat. Cook until heated through; strain through a mesh sieve set over a bowl. Remove baking sheet from oven and transfer to a wire rack; brush heated jam over pears. Let cool briefly before serving warm or at room temperature.