Ingredients
Heap the flour on a work surface and make a well. Pour in the eggs, salt and, if you like, the oil. Knead and roll out a sheet of pasta that is thin but not too much so. Leave it to rest for half an hour, then sprinkle with flour, roll it up and cut out slices of tagliatelle that are half a centimetre wide.
Clean the mushrooms using a small knife to remove any earth from the stalk and rubbing the caps with a soft damp cloth (don’t wash them or they will absorb too much water and lose flavour). Cut the mushrooms into pieces and place in a non-stick pan with two or three tablespoons of extra-virgin olive oil. Add salt and cook over a low heat. Just before removing from the heat, add the finely chopped garlic and parsley.
Boil the tagliatelle in plenty of salted water, drain them when al dente, i.e. not over-cooked, and fry them in a pan with the mushrooms, creaming with two or three knobs of butter.
Four different types of mushrooms with similar features are commonly known as porcini, all of which belong to the Boletus genus: Boletus edulis, B. aereus, B. reticulatus or aestivalis and B. pinophilus. Found under tall trees (such as oaks, beech and chestnut trees), they feature a flat or convex cap that varies in colour from whitish to chestnut brown, with a spongy lower layer and light-coloured flesh that hardly changes when cut. Various mushrooms, both wild and cultivated, are known as field mushrooms, or prataioli. These belong to the Psalliota (or Agaricus) genus, and include the famous champignon mushroom. They are usually whitish-hazelnut coloured, with pink, brown or purple gills and thick stalks that often feature an annulus, or ring. Species of the Russula genus feature a cap that starts off rounded and then becomes convex, with edges that are often uneven and vary a great deal in colour. They have a white, dense flesh that is, however, rather fragile. Finferlo is the Italian common name for Cantharellus cibarius, or chanterelle mushrooms, known as garitola (pronounced "garìtula") in Piedmont. The mixture of mushrooms used in the sauce, which can also be served as an excellent starter, obviously varies according to the fresh produce available: what counts is the overall weight.