Chop the onion and garlic.
Slice the mushrooms into bite-sized pieces.
Heat olive oil in a pan and sauté the onion and garlic.
Add the mushrooms and continue to sauté.
Add the rice and stir, then pour in the white wine and simmer until reduced.
Gradually add vegetable stock while cooking the rice.
Season with salt and pepper.
Mix in Parmesan cheese and butter to finish.