For the dough: put the flour onto a flat surface, make a well and add the eggs, oil, the yeast dissolved in the milk and a pinch of nutmeg and salt. Work everything together by hand to obtain an elastic dough, roll it out and place into a baking tin (a tube pan) in such a way that the edges come over the sides of the tin.
For the filling: grate the cheese, break the eggs and separate the whites from the yolks; whisk the whites with a pinch of salt into stiff peaks, and the yolks in a separate bowl. Once they are well beaten fold them together and gently add the cheese. Pour this mixture into the baking tin, already lined with baking paper, and spread it evenly. With the leftover dough cut thin strips to decorate the fiadone, then turn the borders of the dough that hang over the edge of the tin back over into the cake, and brush the top with the egg yolk.
Bake at 180° in a preheated oven for 45 minutes.