Over medium heat, toast rice in olive oil, stirring constantly until all the rice is coated. Toast for 1 minute, or until grains are aromatic.
Add 1 cup of vegetable stock, the leek and shallot, and turn the heat down to a simmer.
Over the next thirty minutes, stir the risotto frequently and add more stock every time the liquid doesnâ€™t cover the rice.
Add the mushrooms after about 20 minutes.
Taste the rice for doneness â€” theyâ€™re done when theyâ€™re soft and fully cooked, but not mushy.
When the rice is done cooking, remove from heat, stir in the butter and parmesan, and serve.