Preheat oven to 375°F.
In a skillet over medium heat, warm the olive oil.
Add the diced bell pepper and onion and sauté until softened and fragrant.
In a large mixing bowl, combine the cooked rice, cream of celery soup, diced green chilies, sour cream, frozen corn, sautéed vegetables, seasonings, and 1 cup of the shredded cheese.
Stir until everything is well mixed.
Pour the mixture into a greased 9x13 casserole dish and spread evenly.
Cover tightly with foil and bake for 30 minutes.
Remove the foil, sprinkle with remaining cheese if desired, and bake uncovered for an additional 10 minutes, or until bubbly and golden brown on top.