01 - Heat olive oil and 1 tablespoon butter in a large, heavy skillet over medium heat. Add onions and a pinch of salt; sauté 2 to 3 minutes until translucent.
02 - Add garlic and mushrooms; cook, stirring occasionally, until mushrooms are golden and moisture has evaporated, about 7 minutes.
03 - Stir in arborio rice and toast 2 minutes until edges appear translucent.
04 - Pour in white wine and stir until fully absorbed.
05 - Add a ladle of warm vegetable broth, stirring continuously. Allow liquid to mostly absorb before adding the next ladle. Continue, stirring frequently, until rice is creamy and al dente, approximately 18 to 20 minutes. Not all broth may be needed.
06 - Reduce heat to low. Stir in remaining butter, heavy cream, and Parmesan until melted and creamy. Season with salt and black pepper to taste.
07 - Remove from heat, fold in chopped parsley, adjust seasoning, and serve immediately garnished with extra Parmesan and parsley.