Preheat your oven to 400°F. Bake chicken breasts for about 25 minutes until fully cooked, then shred.
In a large baking dish, combine diced onion, bell pepper, minced jalapeño, dry rice, chili powder, garlic powder, cumin, oregano, and sea salt. Stir until well mixed.
In a separate bowl, whisk together chicken broth, tomato paste, and olive oil until smooth.
Pour the broth mixture over the rice and vegetable blend in the baking dish. Stir well to combine.
Add shredded chicken, rinsed black beans, and corn kernels to the baking dish. Stir until everything is incorporated.
Cover the baking dish with aluminum foil and bake for about 50–60 minutes until all liquid is absorbed.
Remove from oven, sprinkle grated cheese over the top of the casserole.
Return to the oven uncovered for another 5–10 minutes until cheese is melted and slightly golden.
Let cool slightly before serving. Garnish with fresh cilantro and chopped green onions as desired.