Roll half of pastry to 1/8-inch thickness on a lightly floured surface; fit into a 9-inch pie plate. Set aside.
Combine 1/2 cup sugar, cornstarch, cinnamon, nutmeg, and salt in a large mixing bowl. Add pears, tossing gently to coat. Spoon into pastry shell.
Combine remaining sugar, flour, butter, brandy, and lemon juice; mix well. Spoon over pear mixture.
Roll remaining pastry to 1/8- inch thickness; cut into 1/2-inchwide strips, and arrange in a lattice fashion over filling. Trim edges; seal and flute. Bake at 350° for 55 minutes. Brush pastry with egg white, and continue baking 5 minutes or until pastry is golden brown.