Kosher salt and freshly ground black pepperKosher salt and freshly ground black pepper
2 tablespoons unsalted butter
1 tablespoon good olive oil
12 ounces cremini mushrooms, stems removed, caps sliced 1/4-inch thick
1/2 cup heavy cream
3 ounces white truffle butter
8.82 ounces fresh fettuccine
3 tablespoons chopped fresh chives, plus extra for garnish
1/4 cup freshly grated Parmesan, plus extra for garnish