Cut the cold butter into small cubes and beat together with the flour until smooth. Add cheese grated on a fine grater, 1 egg yolk and beat everything together. Form the prepared dough into a ball, wrap it in food foil and put it in the fridge for at least half an hour.
Take the dough out of the fridge, remove the food foil and divide it into 2 parts. Roll each part into a thin circle. Cut off the edge of the circle evenly and cut the circle into small triangles.
Use a straw to make small holes. Place the triangles on a baking sheet lined with baking paper.
Bake in a preheated oven at 355 °F / 180 °C for about 10 minutes.