Start by heating a tablespoon of butter in a large pan over medium heat. Add the mushrooms (Cremini, Shiitake, or Portobello work great) and cook until they’re golden brown and softened, about 5-7 minutes. Once done, set the mushrooms aside.
In the same pan, add a bit more butter or olive oil and sauté a diced onion until it’s soft and translucent, about 3-4 minutes. Next, stir in the Arborio rice and let it cook for 2 minutes, making sure it’s coated in the oil and lightly toasted.
Pour in about ½ cup of white wine if you're using it. Stir and let the wine cook off for about 1-2 minutes, adding depth and acidity to the dish. If you're skipping the wine, you can go straight to adding the stock, vegetabe or chicken, whatever you are craving.
Gradually add warm chicken or vegetable stock, one ladle at a time. Stir the rice constantly and wait until the liquid is mostly absorbed before adding more. Continue this process for about 18-20 minutes, until the rice is creamy and cooked through but still slightly firm to the bite.
Once the rice is done, stir the sautéed mushrooms back into the risotto. Remove the pan from heat, then drizzle with truffle oil for that luxurious finish. Serve with a sprinkle of Parmesan cheese and fresh herbs, if you like.