In a large pot or Dutch oven, heat the olive oil and butter over medium heat until melted and sizzling.
Add the chopped onion and sauté for about 5 minutes until it becomes translucent.
Stir in the minced garlic and sliced mushrooms, cooking until the mushrooms are soft and browned, about 5-7 minutes.
Add the Arborio rice to the pot, stirring frequently to coat the rice with the oils and allow it to toast for about 2 minutes.
Gradually pour in the vegetable broth, one cup at a time, stirring continuously. Allow each addition to be absorbed before adding the next. This should take about 20-25 minutes until the rice is creamy and tender.
Once the rice is cooked, reduce the heat to low and stir in the heavy cream and Parmesan cheese until melted and well combined. Season with salt and pepper to taste.
Remove from heat and let it sit for a couple of minutes to thicken up.
Serve the risotto in bowls, topped with a sprinkle of chopped fresh parsley and an extra sprinkle of Parmesan cheese for an elegant touch.
Notes
Serve with extra Parmesan and fresh parsley for garnish.