Heat olive oil in a 4-quart saucepan over a medium heat.
Add onions and garlic and cook for 3 minutes till vegetables become translucent and aromatic.
Add chicken stock and cook till tender for about 10 minutes.
Add rice and lightly toast in oil for 2 minutes while stirring it frequently.
Add the wine 1/3rd at a time stirring until each additional 1/3rd is absorbed.
Once all the liquid is absorbed, remove from heat and stir in Parmesan, parsley, and butter.
For serving, divide into 6 servings and top with shaved truffles.