1Heat the olive oil and butter in a large pan over medium heat.
Add the chopped onion and garlic, and sauté until the onion is translucent.
Add the sliced mushrooms and thyme, and cook until the mushrooms are soft.
Stir in the arborio rice and cook for 1-2 minutes until the rice is well-coated.
Pour in the white wine and stir until it is absorbed by the rice.
Gradually add the vegetable broth, one ladle at a time, stirring frequently. Allow each addition to be absorbed before adding the next.
Continue this process until the rice is creamy and cooked to your liking, about 18-20 minutes.
Remove the pan from heat and stir in the grated parmesan cheese.
Season with salt and pepper to taste, and serve hot.