Sift the flour into a big bowl. Cut the butter into chucks and put in the bowl.
Use your fingers to mix the flour and butter together until it looks like bread crumbs.
Mix the egg yolk and the water together in a small bowl. Take to tablespoons of the mixture and put it in a cup for later.
Add half (or a little more if you like) the cheese to the big bowl. Then add the egg mixture. Mix it with your hands again until it makes a dough. (you may have to use a little of the egg mixture you put to the side).
Roll the dough into a ball and wrap in cling film. Put it in the fridge for around 30 minutes. Pre heat your over to gas mark 5.
Sprinkle some flour onto a clean work surface and roll out the dough until its about as thick as your little finger.
Use cookie cutters to cut lots of shapes from the dough. Place them on a greased baking sheet.
Brush the shapes with the remaining egg mixture and then sprinkle them with the grated cheese.
Bake in the middle of the oven for around 12 minutes until they are golden.