Stuffing:

Cut up a head of radicchio (removing stalk and white parts) and wash in warm water.
Soften the dried porcini mushrooms in water, squeeze them out and cut them up.
Cut up the hazelnuts and toast them in a pan.
Sweat a chopped onion in some oil and add the radicchio, dark red wine and some sugar. Cook until all liquid is removed.
Season to taste the radicchio with some mascarpone (or curd cheese), parmesan, toasted hazelnuts, salt and pepper.

Potato dough:

Press the salted potatoes ( 0,5 kg) through a sieve.
Add a 175 g of soft butter and mix carefully with your hands.
Add 4 egg yolk, nutmeg, salt and pepper and stir properly.
Knead the dough with potato flour and wheat flour in order to obtain a smooth dough.
Cool down in the fridge.

Preparation:

Roll out the dough on the wheat flour in a thin layer.
Cut out circles.
Put some radicchio in the middle of the dough circles with a small spoon and form little balls.
Put into cooking water for approx. 10 minutes and serve with parmesan, radicchio, chive and liquid warm butter.