This recipe is a triple porcini bomb: You use both fresh and dried porcini, plus the water you reconstituted the mushrooms in to cook the rice. You don't need too much fresh porcini for this dish, and I use only the stems. One good-sized mushroom will do. You will also want some dried porcini, too, and these are available in many supermarkets
A word on the rice. I prefer Carnaroli or Arborio rice for this recipe. You absolutely need a risotto rice to make this. No long-grain, OK?