On the work surface, make a volcano with the flour. Inside the volcano, pour the egg, oil and salt and start mixing with the help of a fork. Mix the flour a little at a time together with the rest of the ingredients, to create a mixture that can be kneaded with your hands. It is very important to knead for at least 10 minutes, until you get a dough that recovers its shape after being squeezed with your finger. Cover with a damp cloth and set aside in the refrigerator for 1 hour.

Meanwhile, prepare the filling.

In a bowl, mix all the ingredients except the egg yolk and put them in a sac à poche.

To put aside

Once the rest time of the dough has elapsed, start rolling it out with the help of a rolling pin, giving it a rectangular shape.

The dough must be thin but robust.

Cut the pasta into strips about 10 cm wide and 30 long.

With the help of the sac à poche, create small mounds of ricotta, on which to pour the egg yolk.

Wet the pasta around the ricotta with a little water and arrange the other layer of pasta on top.

Press with your hands following the shape of the filling and with the pastry cutter cut the dough creating circles.

Boil the water in a pot with the salt and, when it boils, add the ravioli one by one and cook for 20 seconds.

In a pan, toast the butter together with a spoonful of truffle paté.

Serve on a plate and, if desired, add grated truffle or coarse salt