Preheat the oven to 350°F (175°C).
In a large mixing bowl, combine the shredded chicken, cooked rice, black beans, corn, diced tomatoes with green chiles, and taco seasoning.
Stir in 1 cup of salsa and 1 cup of cheese to the mixture until everything is evenly coated.
Spread the mixture evenly in a greased 9x13 inch baking dish.
Top the casserole with the remaining cheese and additional salsa if desired.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Once done, remove from the oven and let it cool for 5-10 minutes before garnishing with sliced green onions.
Serve warm and enjoy!