Preheat oven to 400°F (200°C) and grease baking dish with olive oil.

Cut red bell peppers in half lengthwise, remove seeds, and set aside.

Sauté diced yellow onion in skillet until translucent.

Add rice, salt, vegetable stock, diced tomatoes, green onions, and diced pepper. Bring to boil, then simmer for 25 minutes.

Stir in black beans and corn, mixing until well combined.

Fill each pepper half with rice and bean mixture, then top with cheese.

Bake for 40 minutes until cheese is melted and bubbly.

Garnish with cilantro and serve warm.