Heat oven to 425°F. Heat 2/3 cup hot water, butter and salt to boiling in 1-quart saucepan. Remove from heat. Stir in dry potatoes, milk and parsley just until moistened. Let stand about 1 minute or until liquid is absorbed. Whip with fork until smooth; set aside.
In 8-inch skillet, cook sausage and onion over medium heat, stirring occasionally, until meat is no longer pink. Drain if necessary.
In small bowl, mix 1 tablespoon gravy mix and 1/3 cup water. Add to skillet. Simmer until mixture thickens, stirring constantly. Set aside to cool.
Unroll pie crusts. With 3 1/2-inch round cutter, cut 7 rounds from each crust. Spoon about 1 tablespoon mashed potatoes in center of each of 14 rounds; press to flatten slightly. Top potatoes on each with about 1 tablespoon meat mixture. Brush edges of topped pastry with water. Place remaining pastry rounds on top of meat mixture. Pinch edges to seal.
Place on ungreased cookie sheets. Using sharp knife, cut 3 slits in top of each pastry. Brush tops with beaten egg.
Bake 9 to 12 minutes or until golden brown.