Mix eggs, butter, breadcrumbs, nutmeg, lemon zest and cheese with your hands. Mixture must be pliable but firm. Using a meat grinder, put mixture by handfuls into it. (Using the largest size cutter). If mixture is to dry add a little chicken broth. Let the noodles land on a plate cutting the noodles as they leave the grinder at about 2 inch strips. Drop into boiling broth. Simmer until tender...just a few minutes. Sprinkle with grated cheese. Passatelli can be carefully layered between wax paper sheets and frozen then bagged for later use.