01 - Heat olive oil and 2 tablespoons butter in a large skillet over medium heat. Add the sliced mushrooms and cook for 6 to 8 minutes until they are browned and tender. Stir in the minced garlic and cook for an additional minute. Remove the cooked mushrooms from the pan and set them aside.
02 - Using the same pan, add the finely chopped onion and cook for 3 to 4 minutes until it becomes soft and translucent.
03 - Add the Arborio rice to the pan and stir for 1 to 2 minutes, allowing the grains to lightly toast.
04 - Pour in the dry white wine, stirring continuously until it is mostly absorbed by the rice.
05 - Begin adding the warm vegetable broth one ladleful at a time, stirring frequently. Wait until most of the liquid is absorbed before adding the next ladleful. Continue this process for approximately 18 to 20 minutes, until the rice is creamy and cooked al dente.
06 - Return the cooked mushrooms to the pan. Stir in the grated Parmesan cheese, heavy cream, and the remaining 2 tablespoons of unsalted butter. Season generously with salt and freshly ground black pepper to taste.
07 - Remove the risotto from heat, cover the pan, and let it rest for 2 minutes. Garnish with chopped fresh parsley if desired, and serve immediately.