1-Preheat your oven to 400°F (200°C) and: Preheat your oven to 400°F (200°C) and grease a 9 x 13-inch baking dish with olive oil.
2-Trim the tops of three red bell: Trim the tops of three red bell peppers and remove the seeds. Slice two in half lengthwise.
3-In a large skillet, heat olive oil: In a large skillet, heat olive oil and sauté diced onion for about 4 minutes until translucent.
4-Stir in rice, salt, vegetable stock, diced: Stir in rice, salt, vegetable stock, diced tomatoes, and green onions. Bring to a boil, cover, and simmer for 25 minutes.
5-Fold in black beans and corn once: Fold in black beans and corn once the rice is cooked, mixing well.
6-Stuff each halved pepper with the filling: Stuff each halved pepper with the filling and top with shredded cheese.
7-Bake uncovered for about 40 minutes until: Bake uncovered for about 40 minutes until cheese is melted and peppers are tender.
8-Garnish with minced cilantro before serving: Garnish with minced cilantro before serving.