Preheat oven to 400°F. Line a rimmed baking sheet with parchment paper.
Unroll each pie crust on a lightly floured surface and cut out a total of 14–16 rounds (7–8 from each pie crust) using a 3" cookie cutter. Place half of the rounds on the cookie sheet.
In a small bowl mix together mashed potatoes and the ½ teaspoon Hidden Valley® Original Ranch® Dips Mix. Spoon ½ tablespoon mashed potato mixture and ½ tablespoon chopped turkey onto the pie crust rounds, making sure you leave ¼-inch around the outer edge clean. Evenly distribute carrots and parsley over the turkey.
Make the remaining pie crusts slightly bigger (so they will fit over the filling) by pressing with your fingers. Dip your finger in water and run it around the clean edge of the filled pie round. Place another pie round on top and gently press down. Using the tines of a fork press down on the edges to seal them.
In a small bowl, whisk together egg and water. Using a pastry brush, lightly brush the tops of the pies with egg mixture. Poke 1 or 2 slits on the top of the pie so that steam can escape as it bakes.
Bake for about 20 minutes or until golden brown.
Mix sour cream and remaining dip mix together, and serve on the side of the pies. Serve warm.