Heat 3 tbsp olive oil in a wide pan. Add all mushrooms, onion and garlic. Sauté over medium–high heat for 6–7 minutes until lightly caramelised and softened.
Add the Aquarello rice and stir for 1–2 minutes until glossy.
Deglaze with white wine and let the alcohol evaporate completely.
Begin adding the hot water, one ladle at a time, stirring constantly. Add more only when the previous ladle has been absorbed.
Remove from heat. Add the butter and Pecorino, stirring vigorously until creamy. Season with salt and pepper.
Serve in deep plates, grate fresh black truffle on top and drizzle with a little raw olive oil.