Preheat oven to 400 degrees F.
Lightly grease a baking sheet. In a large bowl, combine the chicken and next 7 ingredients. Unroll 1 piecrust onto a lightly floured surface. Roll into a 15-inch circle. Cut out rounds, using a 3-inch cookie cutter. Re-roll dough as needed. Repeat procedure with remaining piecrusts, making 12 to 15 circles total. Arrange 1 round on a clean, flat surface. Lightly brush the edges of crust with water. Place 1 heaping teaspoon of chicken mixture in the center of the round. Fold the dough over the filling, pressing the edges with a fork to seal. Repeat with the remaining rounds and chicken mixture. (Up to this point, the recipe can be made ahead and frozen for up to 1 month). Arrange empanadas on the prepared baking sheet. Bake for 15 minutes.