In a bowl beat the eggs with a pinch of salt. In another bowl combine the breadcrumbs, Parmigiano Reggiano cheese, nutmeg and lemon zest , then add in the eggs , knead the dough until firm and elastic. Wrap the dough in cling film and leave to rest for at least 2 hours. In the meantime, prepare the vegetable broth: dilute the granular bouillon in boiling water, following the instruction on the package. Once the dough has rested, place it in a large-hole potato masher and mash it directly into the boiling broth. Use a knife to cut the passatelli to a length of approximately 4 cm. When the passatelli float to the top, transfer them to the serving bowl with the hot broth. Garnish with shredded chilli pepper and serve.