Pre-heat oven to 350 degrees Fahrenheit.
In a large bowl, mix together white rice, chicken, black beans, chunky diced tomatoes and green chiles, ½ cup shredded cheese, corn, salt, and chili powder. Mix well and set to the side.
Slice bell peppers in half, remove the seeds. Place in a baking dish and begin to stuff with chicken and rice filling. Add the remaining rice mixture around the peppers (it helps them to stay in place). Cover with tin foil and bake for 55 minutes. Remove tin foil and sprinkle the remaining Mexican shredded cheese on top and bake for a remaining 5 minutes or until the cheese is melted and bubbly.
Serve with sour cream and cilantro if desired.
