Rinse rice in a strainer until the water runs clear. Set aside.
Simmer chicken stock in a pot so that it will be warm when you add it to your risotto.
Melt butter in a skillet and add mushrooms, season with salt and sauté over a high heat, about 4 minutes. Transfer to a plate and set aside.
Next heat oil in the same skillet. Add garlic and onion season with salt and sauté until the onion is translucent.
Then with a wooden spoon, gently stir the rice in with the onions and garlic and sauté for two minutes until coated. Add wine and stir continuously on medium heat until wine is absorbed.
Add 1 cup of hot broth stirring until absorbed. Adding hot broth maintains the rice at a simmer. Stir in another cup of broth and stir again until absorbed. Add your third cup of broth along with your cooked mushrooms. Stir again until the broth is absorbed. The rice will start to get creamy. Add the last cup of broth. Stir continuously until completely absorbed, adjusting the heat keeping at an active simmer. Taste for doneness. Season with salt and pepper according to you taste.
Turn off the flame on your stove and stir in the cheese.
From the time that you first added the rice to the skillet and started adding broth will be about 25 minutes.
When your risotto is ready, it should be slightly runny. In Italian, they describe it as all'onda which means wavy. I would describe it as sort of creamy and al dente at the same time. It will even thicken a little as it cools.