Heat oven to 200C
Beat the butter until pale and creamy
Add the cheese and mix
Now stir in the flour and mustard powder a little at a time . Mix thoroughly between each addition
Add the rosemary and stir through
You should have a stiff dough
Roll out n a floured surfaces till about 2mm thick and cut into rounds
Put onto a lined baking tray and bake for about 10 mins
Cool on tray for 2-3 minutes then transfer to a wire rack to finish cooling about 12