For the curd cheese and potato croissants, prepare a dough with butter, flour, potatoes, curd cheese, salt, yolks, cream and sugar. Let rest for half an hour.
Roll out thinly and cut into triangles. Fill each triangle with jam and roll up from the wide side and shape into croissants.
Brush with beaten egg white and bake at 180°C until golden. When cooled, sprinkle the curd cheese and strawberry croissants with powdered sugar.