3. Mix the flour with the salt
4. Beat the butter until creamy
5. Add the sugar and continue beating for a while longer
6. Without stopping beating, add the egg yolk
7. Finally we add the flour and knead until we have a homogeneous dough
8. Store the dough in the fridge for one hour
9. We turn on the oven at 175 ΒΊC
10. With a roller we stretch the dough 7 mm thick
11. Cut the cookies and place them on a baking tray
12. We leave them in the fridge for half an hour with the tray
13. We bake for 12 minutes
14. Remove them and let them cool on a rack
