Pour vegetable stock and wine into a medium saucepan and bring to boil for 5 minutes, then simmer.
In a large saucepan, heat oil and butter. Add the leek and cook over medium heat for 5 minutes, until tender. Add the mushrooms and cook again for 5 minutes.
Add Arborio rice and stir while cooking until the grains become transparent.
Add ½ cup boiling broth, mixing until completely absorbed. Add ½ cup of broth again and stir well. Continue with the rest of the broth, ½ cup at a time.
Cook for 20 minutes or more, until the broth is absorbed, stirring continuously.
Serve sprinkled with Parmesan and freshly ground pepper.