Preheat oven to 400° F.
Place pie crusts on a cutting board and roll each into a 12-inch circle. Cut 3 circles from each crust using a 5-inch bowl as a guide. Gather up remaining dough and roll out on a lightly floured board; cut into 2 more circles.
In a medium bowl, combine pears with brown sugar, cornstarch, cinnamon and nutmeg; toss well to combine. Place equal amounts of fruit onto half of each circle, leaving excess liquid in bowl.
Brush edges of dough with water. Pick up each circle like a taco shell, with rounded sides up, and pinch edges together to enclose filling. Place on a lightly greased baking sheet and press with the tines of a fork to seal. Brush with milk and sprinkle with sugar.
Bake for 15 to 20 minutes, or until golden brown.