Place the butter on center of pastry board with the sugar on one side and flour on the other. Gradually knead in the sugar with the butter, then knead the flour in by degrees. (Dough should look like rich short-crust)
Pat dough into 2 circles about 3/4 inch thick and 7 inches in diameter. Place on baking sheet.
Pinch the edge of dough all the way around and prick all over each with a fork.
Chill dough at least 1/2 hour.
Bake in 375^ oven for 5 minutes; reduce heat to 300^ and bake 45 minutes longer.
Shortbread should be pale gold, not brown -when done.
While still warm cut into small wedges - as this is very rich.
Cut 16 pieces from each shortbread disk.
Great with your favorite jam or jelly too!