Remove any dirt or soil from the truffle very carefully with a mushroom brush. Do not wash as the truffle should be kept dry and not get mushy or spongy.
In heavy bottom stainless pot, sauté the onion with about 2 1/2 ounces butter, cook until translucent. Add the Aborio rice, mix thoroughly and cook about one minute over moderate flame. Add 2 cups of the chicken broth and stir almost constantly. As the rice absorbs the liquid, keep adding it in 1 cup increments until almost fully absorbed, this process should take between 18-20 minutes. Add remaining butter and the cheese (start with 4 oz. then add remaining if necessary). Add the truffle oil - you should now adjust your seasoning with fresh white pepper and kosher salt (taste the risotto before you season - you might not need any salt). Place the risotto into 4-6 bowls - it should have a creamy texture.
Slice truffles (use a truffle slicer) onto each bowl of risotto and serve immediately.
(Note: if you can't afford to spring for the fresh truffles, make the risotto as directed. Do not mix in the truffle oil; instead, drizzle it over the risotto in the bowls just before serving!)
You can serve this risotto as a first course, in the Italian way, or pair it with roasted meat, poultry, game, even grilled fish.