Heat the oil in a large non-stick pan, add the onion and garlic, and fry for 5 mins. Tip in the squash and button mushrooms, and cook for a few mins more. Stir in the rice, then pour in the stock. Stir well, then add the dried mushroom, sage and parsley stalks. Cover and simmer over a low heat for 35-40 mins until the rice is tender – check towards the end of cooking and add a little water if the rice has absorbed all the stock. If there is a lot of liquid, uncover and cook for an additional 5-10 mins.
Take off the heat, fold in the parsley leaves and cheese with some black pepper, then allow to stand for 5 mins before serving.