Bring stock to a simmer in a sauce pan. Add the dried mushrooms to to the cup of hot water and soak until softened and re-hydrated. Reserve the soaking liquid.

Melt the butter in a deep, heavy, medium sized saucepan over medium-high heat. Add fresh mushrooms, re-hydrated mushrooms, onion and garlic or shallot. Saute until softened, about 5 minutes. Add rice and stir to combine.

Add wine and bring to a boil and cook, stirring, until liquid is reduced by half. Add the mushroom liquid, 1/2 cup at a time, stirring enough to prevent the rice from sticking to the pan. Once the liquid is almost completely absorbed, add the vegetable stock, 1/2 cup at a time, stirring almost constantly to create a creamy sauce. Wait until the stock is almost completely absorbed before adding the next 1/2 cup. This will take 25-30 minutes. The rice should be just cooked and slightly chewy.

Stir in the Parmesan cheese and season to taste with salt and pepper. Garnish with a generous dollop on mascarpone and a sprinkle of chopped parsley.