Bring the water to boil in a large pan.
We cut the Guanciale into small cubes and grate the Pecorino on the smallest grater (do not buy it ready grated because it does not have the same intensity). Weigh the spaghetti and the salt.
Put the Guanciale in a frying pan or wok, on a low heat.
When the water is boiling, add the salt (6 g) and then the spaghetti and stir a little so that they don't stick. If you use Spaghetti Barilla no.5, they are ready when the water drops, so do not worry, you don't need a timer.
Beat the yolks a little and add the Pecorino Romano cheese. If the consistency is too dense to mix, you can add 2 tablespoons of the water from the pasta.
Add the other 2 g of salt over the yolks and a generous amount of freshly ground black pepper.
When the water has dropped, but it is still sufficient (the consistency must be more liquid than a sauce), take the pan off the heat (IMPORTANT!).
Then add the yolks over the spaghetti and mix. If the pan is still on the fire when we add the yolks, they will turn scrambled which is not what we want.
If you think you have too much fat from the Guanciale in the pan, you can throw some away. Then add the Guanciale over the spaghetti.
Mix a little and serve.
If you find the consistency too liquid, do not worry, it gets thicker when the spaghetti cool down.