Place the mushrooms into a mug and add hot water. Add the porcini mushrooms and allow to soak for 10 minutes. Drain well.
Place a saucepan over a gentle heat and add the oil.
When hot, add the onion and garlic. Fry over a gentle heat until soft, about 3 minutes.
Add the chestnut mushrooms and fry for a further 2-3 minutes, until browned.
Stir in the rice and coat in the oil.
Add the wine and adjust temperature until it starts to simmer. Stir constantly, until all of the liquid has been absorbed. Slowly add a ladle of stock at a time and simmer. Constantly stir, until the liquid has been absorbed again.
Continue to add the stock, a ladle at a time, until all the liquid has been absorbed. The rice should be plump and tender.
Chop the porcini mushrooms and stir into the risotto gently.
Add the butter to the risotto and allow to melt. Add the salt and pepper to taste.
Finally add the parsley and gently stir.
Roughly chop the soaked porcini mushrooms and stir into the risotto, along with the parsley, butter and salt and pepper. Serve immediately with freshly grated Parmesan.