Using a fine-mesh strainer, rinse rice under running water to remove starch; drain and set aside.
Heat oil over medium heat in a heavy large saucepan (I used a chef's pan which is like a very high sided 10-inch skillet)
Add mushrooms, carrots and onions and saute until the begin to get soft; about 5 minutes.
Add the rice, stir to combine with vegetables and saute until the rice separates and begins to crackle, about 5 minutes.
Heat the stock in a microwave-safe bowl until it just begins to simmer; about 2 minutes.
Add the hot stock to the rice mixture and bring to a boil.
Cover and reduce heat and simmer for 15 minutes or until liquid is absorbed.
Uncover and place a clean towel over the pot (don't let the towel touch the rice), place the lid over the towel and let this sit undisturbed for 10 minutes.
Fluff rice and add the parsely, combining well.