Place stock in medium sized saucepan and place on the back of the stove and bring to a simmer.
Heat a chargrill pan or frying pan and cook chicken fillets, skin side down to crisp the skin and then turn and cook through. When they are cooked remove and slice.
Meanwhile pour olive oil and half the butter into a heavy based casserole or deep frying pan over medium heat.
Add onions, garlic and celery and allow to cook for 5 to 10 minutes or until the onions are soft.
Turn up the heat and add the risotto rice, stirring frequently to coat in the olive oil.
Add the glass of white wine and stir. Cook until the smell of alcohol has gone.
Start adding the heated stock, one ladle at a time, giving the rice a good stir and allowing the stock to absorb before adding the next ladle.
About half way through adding the stock add all the mushrooms except the enoki and stir through.
When the risotto is cooked, it will be soft but still have a little bite, turn off the heat add the rest of the butter and the parmesan. Place a lid on top and leave it for 5 to 10 minutes before giving it a good stir.
Place the risotto on the plate and then arrange the chicken breast on top, using half a breast for each guest.