Mix the two types of flour, add the eggs beaten with salt and work everything together into a homogeneous dough, adding a little water if necessary. Form rolls as thick as a finger and cut them into pieces 2.5 centimeters long. With the tines of a fork, press them together a little and then let them do so in salted water until they rise to the surface. Meanwhile, saute the finely chopped onion in the butter until golden, mix in the walnuts and pour over the chestnut gnocchi. It goes well with black pepper from the mill.