Preheat the oven to 350°F (175°C). In a large skillet, cook the ground beef with the chopped onion over medium heat until the meat is browned and the onion is softened. Stir in the taco seasoning, cooking briefly to allow flavors to meld.

Use a springform pan or casserole dish approximately the size of the tortillas. Spray the pan with non-stick cooking spray to ensure easy removal and serving.

Place one tortilla at the bottom of the prepared pan. Add half the rice, half the Rotel tomatoes, and a sprinkle of cheddar cheese.

Place another tortilla on top. Add one-third of the beef mixture, one-third of the refried beans, half the corn, and a layer of cheddar cheese.

Repeat with another tortilla, one-third of the beans, one-third of the meat, half the remaining Rotel, and cheddar cheese.

For the next layer, use a tortilla, the last of the beans, the last of the meat, the remaining corn, the rest of the rice, and more cheddar cheese. Place a final tortilla on top and cover with the remaining cheddar cheese.

Cover the casserole with aluminum foil and bake for 40 minutes. Remove the foil and continue baking for an additional 10 minutes, or until the cheese is melted and bubbling.

Remove from the oven, allow to rest briefly, and garnish with chopped green onions or fresh cilantro. Slice and serve hot.