Preparation

Mince the meat together with the prosciutto.
In a large heavy pan over gently heat, pour the Extra Virgin Olive Oil and add the minced meat and the celery, onion and carrot kept whole or cut in half. Let the meat just change color, it must remain soft.
Sprinkle the meat with two or three tablespoons of white wine and continue cooking over low heat, allowing the wine to evaporate.
Add the tomatoes deprived of their skins and chopped and the tomato concentrate, mix all the ingredients together and let the ragu cook gently (very low heat) for 2 hours, checking occasionally to see that it is not too dry; if it is, add a very little stock, broth, or white wine.

Meanwhile, soak the dried funghi in a little hot water, squeeze them dry and chop them into small pieces; cook the funghi gently in a little Extra Virgin Olive Oil.
When the ragu' has cooked for two hours, remove the celery, carrot, and onion from the pan. Then add the butter , funghi, mix them all together and let them cook for a few minutes.
Finally, just before serving, turn the heat down as far as possible and sprinkle on the sliced truffle. These must be stirred in very gently and not allowed to cook; the Truffle flavor will be stronger in this way.
Serve with perfectly cooked fresh tagliatelle.

TIP: If you prepare tagliatelle in advance and keep it in the refrigerator, you can simply pre-heat in this way: take a large skilled pan and put 4 tablespoon of Extra Virgin olive oil. Let the oil heat (about 2 minutes) and add the tagliatelle. Stir frequently for 4 minutes, until the pasta is hot. Serve immediately!