Put the porcini mushrooms in warm water, then cut the yellow onions, the celery and slowly heat them up in a pan with the extra virgin olive oil. Diced the peeled potatoes in small pieces, then add them in the pan with the tomato sauce, bay leaf, crust of parmesan, parsley, salt and black pepper. Cover with water and cook until the potatoes will be cooked well.
Remove the bay leaves and the crust of cheese and blend the soup.
Cut the bacon into cubes and chop the mushrooms soaked. Browning all without seasoning in a pan and set aside.
Breaks up the porcini mushrooms pappardelle and cook them in the potato cream, adding hot water if the pasta were dry too.
Add the grated Parmesan cheese, serve the soup enriching it with mushrooms and bacon prepared in advance