Preheat oven to 375° Fahrenheit.
Heat the olive oil in a large skillet over medium heat. Once the oil is hot, add in the diced onion and bell pepper. Sauté the onions and peppers until soft, about 5 minutes.
Add in the ground beef and salt, then break up the beef and cook until it’s no longer pink.
Reduce the heat to low, add in the taco seasoning and water, and simmer for 3-5 minutes until the sauce has thickened.
Transfer the beef mixture to a large 9x14-inch baking dish. Add the rice, black beans, frozen corn, fire roasted diced tomatoes, and chicken broth or water to the baking dish and stir to combine everything.
Cover the baking dish tightly with aluminum foil and bake for 45 minutes, or until the rice is cooked. Then, remove the foil, sprinkle cheese over the top of the casserole, and bake for an additional 5-10 minutes or until the cheese is melted and bubbly.
Remove the casserole from the oven, let it cool slightly before serving.