Heat olive oil in a stockpot.
Add in onions and sweat until translucent.
Add in mushrooms and continue cooking over high heat for another minute.
Add in corn rice and stir until evenly coated with the oil in the pot.
Pour in 2 cups of stock then bring to a boil stirring occasionally.
When level of stock in the pot goes down to level of rice, cover and turn heat to low.
Leave to cook for 10 minutes.
Turn off the heat and leave covered for another 15 minutes.
Preheat your oven to 180C/360F.
Cut the top of each bell pepper. Remove the core and seeds. Stuff with rice pilaf.
Arrange stuffed bell pepper standing up in a deep baking dish.
Pour in remaining stock around the bell peppers.