Bring the stock to a simmer. Heat a large wide pan and add half the butter and oil. Add the spring onions, leeks and garlic and cook for 5 minutes until softened.
Add the rice and stir to coat the rice then tip in the wine and bubble until reduced. Add the stock a little at a time, stirring until the rice is tender with a little bite and oozy (Can add more or less stock depending on how the rice is).
Stir in the parmesan and the rest of the butter and season. Serve hot and season.