Blue cheese biscuits with poppy seeds

Preheat the oven to 200C. Line 2 baking sheets with baking paper. In a bowl, mash the cheese with a fork. Add the butter and egg yolk and mix together. Sift over the flour, add the polenta and mix to a stiff dough. Shape into a ball, flatten slightly, wrap in cling film and chill in the freezer for 15 minutes. Dust a work surface with a little flour. Roll out the dough to a thickness of 5mm. Using a 5cm star cutter, cut out biscuits and put onto the baking sheets. Re-roll out the trimmings so all the dough is used up. Sprinkle the biscuits with poppy seeds, pressing them in slightly so they stick. Bake for 12-15 minutes until golden. Transfer to a wire rack to cool.These will keep in an airtight container for a week