Peel the potatoes and cook them until cooked without salt.
Press hot potatoes through the potato press and immediately knead into a dough with egg yolks, flour, potato flour, nutmeg and salt.
Carefully roll out the dough in portions, cut into triangles and roll each into a croissant. Whisk the cream with the egg yolk and brush the croissants with it.
Bake in the preheated oven at approx. 150-160 degrees for about half an hour on the middle rack (bottom and top heat) until cooked.
My advice:
Add some truffle butter to the hot potatoes. But then, as the dough becomes more moist, work in more flour and potato flour.