Drain apricots, reserving 1/2 cup juice; set apricots aside. In a saucepan, combine egg yolk, milk and reserved apricot juice; stir in the pudding mix until smooth. Bring to a boil over medium heat; cook and stir until thickened. Chop 1/2 cup apricots; add to pudding. Pour into pastry shell. Refrigerate.
For glaze, combine cornstarch and apricot nectar in a saucepan until smooth. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Cut the remaining apricots into thirds; arrange over pudding layer. Spoon glaze over top. Sprinkle with almonds. Chill until serving.