01 - Heat 1 tbsp butter in a large skillet over medium heat. Add the mushrooms and cook until golden and their liquid has evaporated, about 6–8 minutes. Set aside.
02 - In a large saucepan, heat olive oil over medium heat. Add onion and cook until translucent, about 3 minutes. Stir in garlic and cook for 1 minute.
03 - Add the arborio rice, stirring to coat each grain with oil. Toast for 2 minutes until edges become translucent.
04 - Pour in the white wine and stir until fully absorbed.
05 - Add warm vegetable broth, one ladleful at a time, stirring often. Allow each addition to be absorbed before adding the next. Continue until the rice is creamy and al dente, about 20–25 minutes.
06 - Stir in the sautéed mushrooms, Parmesan cheese, and 2 tbsp butter. Season with salt and pepper.
07 - Remove from heat and drizzle with truffle oil. Gently mix, then serve immediately, garnished with chopped parsley if desired.