While the dough sits in the fridge, you have time to prepare the filling.
In a bowl, combine the farmers cheese with the crumbly cheese (I used Romanian telemea or feta cheese) and the egg.
There was no need for me to add more salt, because the cheese was salty enough, just taste and adjust.
If the cheese mixture is too watery, add 2-3 tbsp semolina, to soak up excess liquid in the filling.