Steps
1. In a saucepan, heat the vegetable broth and keep it warm over low heat.
2. In another pan, heat olive oil and butter over medium heat. Add the chopped onion and sauté until translucent.
3. Add minced garlic and sliced mushrooms, cooking until the mushrooms are soft.
4. Stir in the Arborio rice, toasting it for about 2 minutes until slightly translucent.
5. Begin adding the warm broth, one ladle at a time, stirring continuously until the liquid is absorbed before adding more.
6. Continue this process until the rice is creamy and al dente, about 18-20 minutes.
7. Stir in the grated Parmesan cheese, and season with salt and pepper to taste.
8. Serve hot, garnished with fresh parsley if desired.