Ingredients
175g plain flour, plus extra for dusting 
115g butter 
50g of caster sugar, plus a little extra for sprinkling 

Method

Put all ingredients into a mixing bowl and rub the ingredients together until the mixture looks like breadcrumbs.  You now need to squeeze the mixture to bring together as a dough, it is a very buttery recipe so will work, be firm. Wrap in cling film and put into the fridge for 30 minutes. 

After 15 minutes preheat the oven to 170c. 

Line a baking tray and roll out the dough to a circle.  You can also push down with your hands to shape, I like the rustic look of this but either works well. Now you need take a blunt knife through the middle of the dough gently score, turn 90 degrees and again run your knife gently through the middle so you have a cross, turn 45 degrees and make another cross.  This should give you 8 pieces of shortbread. 

Cook in the oven for 15-20 minutes until golden.  Remove from the oven and with a knife cut through your lines so you have individual biscuits.