Preheat the oven to 350 degrees . Using a food processor, grind 1 cup turkey for about 5 seconds. Transfer to a medium bowl. Add the remaining chopped turkey, potatoes, pumpkin pie filling, cumin and curry powder. Season with salt and pepper.
On a lightly floured surface, roll out the puff pastry dough 1/8 inch thick. Using a 3-inch round cookie cutter, cut out 32 disks, gathering the scraps and rerolling.
Place 1 tablespoon of turkey mixture on each disk. Dampen the disk rims with water and fold the dough over into a half-circle, pressing the seams with a fork to seal.
Beat the egg with 2 teaspoons water. Place the samosas on 2 nonstick baking sheets and brush with egg wash. Bake, switching the pans halfway through, until golden, about 25 minutes; serve warm.