Heat the olive oil and 1 tablespoon butter in a large skillet or saucepan over medium heat.
Add the onion and garlic, cooking until softened.
Toss in the mushrooms and cook until they release their juices and turn golden.
Stir in the Arborio rice and cook for 1–2 minutes until lightly toasted.
Pour in the wine and stir until absorbed.
Begin adding the warm broth one ladle at a time, stirring often and allowing the rice to absorb liquid before adding more.
Continue this process until the rice is creamy and tender, about 18–20 minutes.
Stir in the remaining butter and Parmesan cheese. Season with salt and pepper.
Garnish with fresh parsley and serve warm.