I use salted butter, which seems to enhance the flavour.
They are very easy to make and keep for about 1 week in an airtight container.
6oz plain flour
6oz salted butter, softened
3oz golden caster sugar
Beat the butter and sugar together until light and fluffy.
Seive the flour and add to the semolina, gradually add to the creamed butter and sugar until a dough is formed (this can all be done in a food mixer).
Pre-heat the oven to 150C
Roll the dough lightly to form a round to fit a 20cm fluted tin, press into the tin and prick all over with a fork.
Bake for 1 hour until the shortbread is golden brown.
Remove from the oven and cool in the tin. Before the shortbread cools completely mark out wedges with a sharp knife.
Break into wedges and store in an airtight container.