In a saucepan, sauté the mushrooms in the oil. Season with salt and pepper. Set aside.
In the same saucepan, brown the shallots in butter. Add the rice and cook for 1 minute over medium-high heat, stirring to coat.
Deglaze with the wine and cook over medium heat, stirring until the liquid is almost completely absorbed. Add the broth, about 180 ml (3/4 cup) at a time, stirring frequently. Add broth when the wooden spoon leaves a trace in the rice. After about 20 minutes, the rice should be al dente, having absorbed almost all the liquid and have a creamy consistency.
Add the cheese and mushrooms. Adjust the seasoning. Add truffle oil, if desired.
Season with pepper and sprinkle with Parmesan shavings.