Break the eggs and add the breadcrumbs, followed by the grated Parmigiano Reggiano, chopped Prosciutto di Modena, lemon zest, nutmeg and salt. Press into a block and leave to rest for 30 minutes.
Crush the garlic and fry it gently in the extra virgin olive oil until golden. Add the mushrooms, cover with a lid and cook for five minutes. Remove the lid and continue cooking for another 15 minutes, adding the milk and a knob of butter. Leave to reduce for a few minutes, then add the Parmigiano Reggiano.
Meanwhile, make the passatelli, using a potato masher and cook them in boiling salted water for three minutes. Toss in the sauce, decorate with a few parsley leaves and serve.
The quantities indicated are enough for four people.