Add the egg yolks to the flour and mix everything with patience until you get a solid and elastic dough.
Cover the dough with cling film and let it rest for about 20 minutes.
Dust the work surface with flour and roll out the dough thinly with a rolling pin.
When the dough has reached a thickness of 2 mm, fold it on itself: start from one edge, folding it over until you obtain a rolled strip.
Then with a very sharp knife, cut this rolled strip into very thin slices that will unroll to become tajarin.
How to prepare the Tajarin:
In a large pot, bring plenty of salted water to a boil and cook the tajarin until al dente, about 2 to 4 minutes.
In the meantime, scrub the truffle with a brush or damp cloth to remove any earthy residues, peel it, and grate half of it. Slice the other half with a truffle slicer and set aside.
Melt the butter in a large pan and add the grated truffle, then add the cooked pasta.
Add a generous sprinkling of grated Parmigiano Reggiano cheese and let the flavors mix for a few minutes, stirring with a wooden spoon.
Transfer the seasoned tajarin to a serving dish and serve immediately, sprinkled with the remaining sliced truffle and a pinch of salt.