Heat the olive oil in a large saute pan. Add the shallot and garlic and cook on a medium-low heat until softened.
Add the mushrooms and cook for a further minute.
Stir in the risotto rice and immediately pour in the stock and vinegar (if using). Bring to a boil then reduce to a simmer for approximately 30 minutes or until all the liquid has been absorbed and the rice is cooked. Add more hot water, if necessary.
Once cooked, stir in the nutritional yeast (if using), stir in a handful of chopped fresh parsley and season with salt and pepper.