The shortbread has a history as a Scottish dessert. The name Short originates from Shortening originally done with use of lard (pig fat) but later contemporary cuisines have stopped using lard and use butter. Shortening is often referred to by use of margarine but in shortbread margarine shall not be used.
The baking of shortbread is easy enough :
pinch of salt
200g butter (not margarin!)
Mix flour, salt and sugar.
Rub in the butter (melt it a little first to make it softer).
Work the mixture to a smooth, pliable dough.
Divide the mixture in 2 and put in a small baking tray (use 2 small round tins, approx 20 cm in diameter). Flute the edges and prick all over with a fork.
Bake for 40-45 mins at 160 degrees in the centre of the oven.
Sprinkle with extra sugar and cut into pieces while still warm.