Preheat oven to 375 degrees. Divide each circle of pie crust into quarters along fold lines. On a lightly floured board, roll each piece into a 15 cm circle. In a medium bowl, combine apples, walnuts and flour. In another small bowl, combine sugar, cinnamon and nutmeg. Spoon about quarter cup apple mixture in center of each circle of pastry. Sprinkle about 2 teaspoons sugar mixture over apples on each pastry round. Fold dough in half over apples; press edges with a fork to seal. Dip both sides of each turnover in melted butter. Place buttered turnovers in a 38 cm x 25 cm jelly-roll pan. Sprinkle remaining sugar mixture over turnovers. Bake in preheat oven 15 to 20 minutes or until golden brown. Serve warm.