3/4 pound (350 g) porcini
2 shallots
3/4 pound (350 g) canned tomatoes
A small bunch of parsley
A clove of garlic
The leaves of a sprig of rosemary
A few leaves of sage
Olive oil
Dry white wine
Salt & pepper
Heavy cream (optional, see below)
Freshly grated Grana Padano or Parmigiano Reggiano
Clean the mushrooms, brushing the dirt away from the stems, and separate the caps from the stems; dice the stems and cube the caps, keeping them separate.
Mince the shallots and the herbs and sauté them for a few minutes in 4 tablespoons of oil in a casserole. Add the diced stems, cook another minute, and then add a half cup of wine and the tomatoes. Season with a little pepper and simmer the mixture over a very gentle flame for a half hour. Add a little more wine and a drop of water (or the liquid the mushrooms steeped in if you are using dried mushrooms), and the cubed caps.
Continue simmering the sauce over a gentle flame. Depending upon how much moisture the mushrooms contain you may need to add more liquid -- a splash of wine and a little hot water, or if you'd rather a quarter cup of heavy cream, and, if need be, a little water.
In the meantime bring pasta water to a boil, salt it, and cook the pappardelle. Drain the pasta and season them with the sauce; serve them with grated cheese for those who want it.