Preheat the oven to 180 degrees C, 360 F or Gas mark 4
Cream the butter and sugar.
Add the plain flour and semolina or cornflour. Mix lightly until it just comes together.
Roll out to 1/2 cm thick and cut into cookie shapes. Use a fork to add markings to each cookie.
If making the triangle version then roll the dough into a circle about 1cm thick and put into a round baking tray. Cut lines without cutting right through to divide into 8. This will allow you to separate the cookies when baked. Use a fork to add markings to each cookie.
Bake for 15-20 minutes. Sprinkle with sugar.