1. The first thing to do is to get the stock on over a medium heat. Then into a separate pan add a drizzle of olive oil and 1 knob of butter. Add the onions, garlic, leeks, celery, thyme leaves and season. Slowly fry the veg for 5 minutes.
2. While the veg is softening take half of the mushrooms and roughly chop, add to the pan and continue cooking for another 5 minutes.
3. Turn up the heat to high and add the rice. Make sure you keep stirring and after a minute or so the rice will start to go a little translucent. At that point, it’s time to add the wine. Keep stirring until the wine has almost gone.
4. At this point, it’s time to reduce the heat to low and add your first ladle of stock. Only add one ladle at a time and continue stirring allowing the rice to absorb the stock before adding the next one. This will take around 20 minutes to cook, you want the rice to have a very slight bite to it, or of course if you prefer the rice more well done just keep cooking and adding the stock. You may need a little more or little less stock so just keep checking the rice; if you run out of stock and need more just add boiling water.
5. When the rice is almost ready take the  remaining mushrooms and king oyster leaving any small ones whole and breaking up any big ones and fry over a medium to high heat with a drizzle of olive oil, a knob of butter and season. Cook for a couple of minutes then tip out onto some kitchen paper.
6. To finish the risotto take the pan off the heat, add half of the fried mushrooms, the butter, Parmesan mix well and allow to just sit there for a minute. Check for seasoning and pop the remaining fried mushrooms on top with a few thyme leaves and a drizzle of the truffle oil or extra-virgin olive oil. 

A good risotto should oozy like lava on the plate so if it’s a bit stodgy add a little stock or water to the pan to loosen it up.