Favorite Christmas Cookies

Cream shortening, sugar, orange peel, and vanilla thoroughly. Add in egg and beat until light and fluffy. Add in the milk and mix. Sift dry ingredients together, then blend into cream mixture. Divide dough in half (thirds if you double your recipe), slightly flatten between two sheets of waxed paper, then refrigerate for one hour (or freeze for 20 minutes). While dough is chilling, combine egg yolk, water and food coloring to make the egg yolk glaze. Roll out dough on lightly floured surface and cut into shapes with a cookie cutters. Transfer shapes to lightly greased cookie sheet and paint cookies (with a soft brush) with egg yolk glaze. After brushing with egg yolk glaze, bake at 375 degrees for approximately 6 minutes. Do not allow the cookies to brown. While cookies are baking, mix powdered sugar, milk and egg whites (which are optional) to make the decorative icing. Remove cookies from oven to a wire rack to cool. Then, using a pastry bag or Ziploc bag, pipe with white icing to decorate. Note: when making the white decorative icing, make sure that it is thick and somewhat retains its shape.