Cream butter, add honey, and blend together until light and fluffy.
Force the hard-cooked egg yolk through a sieve, and add to the butter-honey mixture.
Add beaten egg yolk, citrus peel, vanilla, and salt.
Mix well, then sift flour and add to dough.
Form into a ball, wrap in plastic wrap, and chill for about an hour (not longer or it becomes too stiff to handle).
Roll out the dough on a floured board to form a 15-inch square about 1/8 inch thick.
Cut into 3-inch squares, place 2 teaspoonfuls of apricot glaze in the center of each square and fold dough over to form a triangle.
Seal edges by pressing firmly with your thumb or the tines of a fork.
Place on a large, buttered, floured cookie sheet and chill for a half-hour.
Preheat oven to 350° F.
Brush the top of each triangle with egg white, cut a small gash in the center of each folded edge, and bake in preheated oven for 12 minutes.
Remove from baking sheet carefully, and cool on wire rack.