Mix the cheese, breadcrumbs, nutmeg and lemon zest together well in a large bowl. Then form a hollow in the middle. Beat the eggs in the well and then stir slowly with a fork and mix with the rest. Work everything into a firm dough and then let it rest for 5 minutes at room temperature.
Bring the beef broth to a boil. Use a potato press to squeeze the dough into pasta about 4 centimeters long. Add the passatelli to the broth. When the passatelli float to the surface of the broth, they`re done.
Put the broth with the passatelli in the plates, sprinkle with a little parmesan if you like and serve immediately.