This is a dish I started to cook 2 years ago and which I repeated in this Porcini season.
The chestnuts were from my own Chestnut tree, not the big "Maroni", smaller ones, but delicious. You really have to clean them thoroughly! Both skins and the thin second one is the problem. But it is hard and bitter if you keep it. And all the wonder methods they offer on the web to clean chestnuts work only half. So it is a pain...
Two years ago I bought the porcini mushrooms on my way from San Filippo to Orvieto at a little Veggie Shop. They were nearly dry and somewhat soft. "It is from the Tramontana " (a cold strong wind from the North) told me the woman in the shop. Well I got away with more than 1 kg of Porcini for 20 € ?
I cleaned them at home and boiled them for 3 minutes in a water/wine mixture - and they were perfect after this treatment. 3 parts came into the freezer and the 4th part were made to this chestnut soup.
Yes, garlic, spring onions, even a bit of Chily..and I used the cooking water of the mushrooms as the broth.. You cannot imagine how good this was.
This year porcini were of a wonderful quality. (and astonishingly cheap for 23 €/kg). I got a good amount from my veggie monger at Bolsena. Beside some other dishes I repeated the soul. This time I started with a "Soffritto" from celery stems, carots and onions. In this way the soup becomes more dense and aromatic.
If you want carbs with this, roast pieces of bread in olive oil. Some Parsil is good.
On the first version I was convinced only a red could match this strong taste of forest and actually a good Umbrian Sangiovese fits heavenly. I tried Accordo from "The Vellette" and "Antajir" from " il Palagione." But tasting the "sofritto version" of the soup I got the idea of Grechetto, but a big Grechetto like Nuricante from "Duca della Corgna" or even something more.