Preheat a large pot over a medium heat. Melt the butter, then add the chopped mushrooms and a sprinkle of salt. Cook for 5-10 minutes until shrivelled and golden brown, then remove from the pot and set aside.
Add the leek greens, sage and water to the pot. Pop a lid on and cook for 5-10 minutes or until the leek greens are thoroughly cooked and wilted. They take longer to cook than the whites but will also receive further cooking time with the risotto.
Allow the liquid to cook off the leeks entirely or pour it out into a bowl to add back into the risotto later.
Push the leek greens to one side of the pot then add the oil and rice. Toast the grains for 3-5 minutes until they become translucent.
Stir the rice in with the leek greens then pour over the white wine. Allow it to cook off, then begin adding water in approximately ½ cup increments. Allow the first ½ cup to cook off, stirring regularly, before adding the next ½ cup. Repeat until you have used all the liquid or your risotto grains are fully cooked and the risotto creamy in texture.
If you are using the miso paste, dissolve it in the water as you add it to the risotto. This will add extra umami to help emphasise the mushroom flavour. Add the sage powder here too if you are using it.
Once your risotto is cooked through and creamy, remove it from the heat. Stir in the cooked mushrooms leaving some for garnish if you like.
Gradually stir in the freshly grated parmesan then add pepper and vinegar or lemon juice to your tastes. Add extra salt here if necessary – it’s best to salt after adding the parmesan.
Serve as is or with a good drizzle of truffle oil and some extra parmesan.