Start by cooking the brown rice according to the package instructions. Once cooked, set it aside.
Preheat your oven to 375°F (190°C).
In a large skillet, heat 1 tablespoon of canola oil over medium heat. Add the chopped onion and minced garlic, sautéing until fragrant and the onion is translucent, about 3-4 minutes. Increase the heat and add the diced chicken. Season with chili powder, cumin, paprika, salt, and black pepper. Cook until the chicken is browned and cooked through, about 5-7 minutes.
Once the chicken is cooked, stir in the can of tomatoes with green chiles, black beans, corn, cooked rice, fresh cilantro, and lime juice. Mix well and cook for an additional 2-3 minutes until heated through.
Slice the tops off the bell peppers and remove the seeds. Lightly brush the outsides with the remaining canola oil and place them in a baking dish.
Spoon the chicken and rice mixture into each bell pepper, packing it in as needed. Sprinkle the tops with shredded cheese.
Cover the baking dish with aluminum foil and bake for 25 minutes. Then, remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and the peppers are tender.
Once baked, let the peppers cool for a few minutes. Garnish with additional cilantro and serve with sour cream and hot sauce if desired.