For the vol-au-vent
First you need to prepare the vol-au-vent. Spread the puff pastry with a thickness of about 0.5 cm, if you bought it use that one should not roll it further. The vol-au-vents are easy to make, just cut with "copapasta" (pasta cutter) the puff pastry in which you are going to overlap one or two rings of puff pastry (depending on how high you'll want your vol-au-vent), the rings will be made €‹from puff pastry of the same size as those used as the base, but at the center will be cut away a small disk of dough. Once you get the vol-au-vent brush them with egg yolk and bake at 180-200° C for about 10-15 minutes.

For the filling
In a saucepan, melt the butter over a very gentle heat, add the flour and mix well. Add the hot milk, salt and pepper and put in according to your taste nutmeg. Add the grated fontina cheese in flakes and bring to a boil, so you will get a thick cream. At the end add the egg yolks and Parmesan cheese and mix well.
The sauce is now ready to be poured inside the vol-au-vent that you will have s
lightly warmed in the oven.

The number of vol-au-vent depends on their size, in this case we have made the little ones with a diameter of 4 cm and they have come up approximately 50.

Fontina DOP cheese is the most popular and well known in the Valle d'Aosta, derives its name from the Font, a pasture near Quart (Aosta in the suburbs), and has become known and appreciated in Italy and in the world thanks to the methods of preparation that have in Val d'Aosta a secular tradition.
Fontina, as good as a table cheese, it is also an excellent ingredient in many culinary preparations typical of the Aosta Valley as croutons, soups, fondue sauce, polenta, etc. ..
www.Tiraccontounaricetta.it wanted to use the cheese to create a creamy and delicious sauce to use as a filling for the vol-au-vent of puff pastry.

Each vol-au-vent
Energy: 88.34 Kcal
Total Dietary Fiber: 0.17 g
Alcohol: 0.00 g
Water: 14.37 g
Total Protein: 2.33 g
Animal protein: 1.76 g
Vegetable protein: 0.57 g
Total lipids: 6.89 g
Lipids animals: 6.83 g
Plant lipids: 0.06 g
Cholesterol: 29.64 mg
Available carbohydrates: 4.53 g
Starch: 3.82 g
Sugars: 0.72 g