1. Chop the onion and sauté in the olive oil over medium heat, turning often until translucent.
2. In the meantime, preheat the oven to 400 degrees Fahrenheit. Rinse the peppers well, then remove stems and cores and slice in half. Spray a metal baking sheet with oil and place the peppers on it, skin side up. Cook for 10 minutes.
3. Next, combine cooked rice, beans, and corn in a mixing bowl. Chop the tomato and add to the mixing bowl with the juices. Chop the parsley and add it in with the salt, cumin, and garlic. You can also reserve some of the parsley for garnish. When onion is cooled, add it to the mixture and combine.
4. Stuff the peppers with the rice and bean mixture and sprinkle with cheese. Lower oven to 350 degrees Fahrenheit and bake for 20 to 25 minutes.
To cook the beans, cover with water in a pot and boil for two minutes. Let sit for half an hour and discard the water. Cover the beans with water again and simmer for one hour, adding a dash of kosher salt halfway through the cooking time.