Add the semolina (keeping 20/30 grams aside), the Parmesan and a pinch of salt.
It’s better to start with less semolina flour because the amount of semolina absorbed depends on the size of the egg (small, medium, large).
Pulse a few times. If the semolina is still very sticky add a little more and run the mixer again ... it should begin to form coarse pieces.
Pulse again adding more flour if necessary but keeping in mind that the more flour you add, the smaller the pieces will be.
Once the grattino is the size you want put it and no longer sticky spread it out onto a cloth or in a dish to dry before cooking (at least 1 hour). The grattino will cook in just a few minutes. If you are cooking it in broth once the pieces rise to the surface, they are ready!
Once dried, you can store the extra grattino in a glass jar. Keep it in a cool and dry place. The important thing is that the pasta is dry and doesn’t stick together
Notes
This pasta can be used in broths and minestrone type soups.