Prepare the Mushrooms: In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the mushrooms and sauté until they are soft and lightly browned, about 5-7 minutes. Season with salt and pepper. Set aside.

Cook the Risotto: In a large, heavy-bottomed saucepan, heat the remaining olive oil over medium heat. Add the onion and garlic, sautéing until the onion is translucent, about 2 minutes.

Toast the Rice: Add the Arborio rice to the saucepan, stirring constantly, until the edges of the grains start to become translucent, about 2 minutes.

Deglaze: Pour in the white wine and stir until it is fully absorbed by the rice.

Add the Stock: Begin adding the warm stock, one ladle at a time, stirring frequently. Wait until the liquid is almost completely absorbed before adding the next ladle. Continue this process until the rice is creamy and al dente, about 18-20 minutes.

Mix in the Mushrooms: Add the cooked mushrooms to the risotto, stirring gently to combine.

Final Touches: Remove the pan from the heat. Stir in the butter, Parmesan cheese, and truffle oil. Adjust the seasoning with salt and pepper to taste.

Serve: Spoon the risotto into bowls. Garnish with fresh truffle shavings and chopped parsley, if desired. Serve immediately.