01 - Heat 2 tablespoons olive oil and 1 tablespoon butter in a large heavy-bottomed pan over medium heat. Add chopped onion and cook until translucent, about 3 minutes.
02 - Add minced garlic and cook for 1 minute until fragrant.
03 - Stir in sliced mushrooms and cook for 6 to 8 minutes until softened and liquid has evaporated. Season with salt and black pepper.
04 - Add Arborio rice and stir continuously for 2 minutes, allowing the grains to toast lightly and develop a translucent edge.
05 - Ladle warm vegetable broth one cup at a time into the rice mixture, stirring constantly. Wait until most of the liquid is absorbed before adding the next ladle. Continue for approximately 20 to 25 minutes until rice is creamy and al dente.
06 - Stir in remaining 2 tablespoons butter and freshly grated Parmesan cheese until melted and creamy.
07 - Remove from heat, drizzle with truffle oil, sprinkle chopped parsley, and adjust seasoning if necessary.
08 - Serve immediately, garnished with extra Parmesan and parsley.