Place flour in a large bowl, add sugar and salt and mix well.
Shred the cold margarine and shortening, add to the flour and rub in until the mixture looks like fine breadcrumbs.
Add cold water to the flour mixture and gently mix to form a pastry dough. Do not knead.
Cover the pastry and place in the refrigerator to relax for about 15-18 minutes.
Lightly dust the work surface with flour.
Remove the pastry from the refrigerator and place it on the floured work surface.Use a lightly floured rolling pin to roll out the pastry.
Use a 3 1/2 - 4 inch cutter to cut rolled pastry into circles.
Crimp the edge using the thumb of one hand and the thumb and forefinger of the other hand.
To make the coconut filling, heat a sauce pan over medium low heat and add water.
Add grated coconut, brown sugar, nutmeg, vanilla extract, salt (optional), and butter.
Stir until the liquid has absorbed and the mixture begins to stick together.
Remove coconut mixture from heat and allow to cool.
Place the dough on a cookie sheet, fill each with about three tablespoons coconut mixture and bake in a pre-heated oven at 205 degrees C or 400 degrees F for 15-20 minutes.