mixture at the center of each circle; brush edge of pastry with egg white mixture. Fold pastry circle up over filling; press edge with fork to seal. place empanaditas on ungreased cookie sheet. Repeat with remaining pastry circles. Gather any remianing pastry; shape into another round. Repeat rolling cutting and filling. Beat egg yolk and milk until well blended; brush over tops of empanaditas. Bake until golden brown, 15 to 20 minutes. Serve warm.