Wash the potatoes and cook covered in boiling water for about 25 minutes. Drain the potatoes, rinse with cold water and drain. Peel potato skin. Press the still warm potatoes through the potato press.
Stir the semolina with a mixing spoon into the potato mixture. Stir in starch and egg yolk. Season with salt, pepper and nutmeg, cool down.
Form the dough into finger-thick rolls on a floured work surface and cut into pieces of about 3 cm in length. Shape each into oval dumplings. Press in the gnocchi with a fork. Bring 3-4 l salted water (approx. 1 teaspoon salt per litre) to the boil in a wide saucepan.
Cook the gnocchi in portions for about 5 minutes (do not cook!). Lift out with a skimmer and drain.
Clean the peppers, cut lengthwise, remove seeds, wash and cut into strips. Wash the sage, shake dry and pluck the leaves. Heat the oil in a large frying pan, fry the coppa in it until crisp and drain.
Steam pepperoni and sage in hot frying fat for about 1 minute. Add butter and froth up briefly. Warm the gnocchi in it while tossing. Break the coppa into pieces and fold into the gnocchi. Season with salt and pepper.
Pecorino over it.