Blend together 1/4 cup sugar and cornstarch in saucepan. Stir in grapes, pear, ginger and nutmeg. Bring to simmering over medium-high heat, stirring. Simmer 8 minutes or until mixture has thickened. Let cool.
Heat oven to 400 degrees F.
Cut pastry in half parallel to the fold lines. Roll out each half with a floured rolling pin on a floured surface, one into a 15 x 7-inch rectangle, the other into a 14 x 6-inch rectangle.
Place the smaller rectangle on a greased baking sheet. Spread filling lengthwise down center in a 3-inch-wide strip, leaving a 1 1/2-inch border. Fold larger pastry lengthwise in half. Along folded edge, cut slits, about 3/4 inch apart and 2 1/2 inches long.
Brush edges of bottom pastry around filling with egg. Top with larger pastry, pressing edges. Use tines of a fork to seal. Brush top with egg. Sprinkle with remaining tablespoon sugar. Trim edges with a sharp knife.
Bake at 400 degrees F for 20 to 25 minutes, until golden. Cool to room temperature. Makes 8 servings.