Boil half of the stock and pour over the dried mushrooms allow to soak for 30 minutes.
Melt 20g of the butter in a suitable sized saucepan and add the shallots, cook gently until starting to soften then add the rice.
Stir well to coat the grains then add the vinegar and turn up the heat allowing the vinegar to reduce until almost evaporated.
Carefully add a ladle of the vegetable stock stirring well.
Add the stock paste or powder and continue adding the stock
Carefully decant the mushroom liquor from the dried mushrooms and add gradually.
When the rice is cooked season with a little freshly ground black pepper.
Add in 20g of butter, some parmesan and the mascarpone.
In a frying pan add the last of the butter and heat over a high heat until starting to foam.
Add the mixed mushrooms and sauté until lightly cooked then scatter in the chopped parsley.
Spoon the risotto into warm bowls and then top with the mushroom mixture.
Shave over the truffles if using then serve.