If making homemade salsa verde, prepare it up to 5 days ahead; otherwise use store-bought salsa verde.
Preheat the oven to 375°F (190°C).
In a 13x9-inch casserole dish, combine the diced green bell pepper, minced garlic, chopped chicken, chili powder, uncooked white rice, and corn.
Stir in the salsa verde, low-sodium chicken broth, and sea salt until everything is evenly mixed.
Fold in half of the shredded cheese (about 1 cup).
Cover the dish tightly with foil and bake at 375°F for 45 minutes, or until the rice is tender and the chicken is cooked through.
Remove the foil, stir the casserole gently, then sprinkle the remaining 1 cup of shredded cheese evenly on top.
Set the oven to high broil and broil the casserole 5 to 8 minutes, watching closely, until the cheese is golden brown.
Let the casserole rest a few minutes, then serve with optional toppings such as cherry tomatoes, avocado, lime wedges, cilantro, or sour cream if desired.