In a bowl, mix the breadcrumbs, grated Parmigiano Reggiano, nutmeg, and lemon peel.
Meanwhile, bring the chicken broth to a boil.
Break the eggs and add them to the dry ingredients.
Mix with your hands until it forms a smooth, even ball.
Place the dough in a potato masher and mash directly into the boiling broth.
Cook the passatelli for 1 minute, until they rise to the surface.
Serve piping hot along with a generous portion of the broth.
