Preheat oven to 375-degrees F. and spray a 9x13-inch casserole or baking dish with cooking spray.

In a large mixing bowl, combine the cream of chicken soup, sour cream, diced tomatoes, frozen corn, half (1 c.) of the shredded cheese, Ranch seasoning mix, and Montreal steak seasoning. Mix well.

Stir in the shredded rotisserie chicken. Set mixture aside.

Layer the casserole. Spread half the frozen hashbrowns into the prepared dish, then spoon the chicken mixture over the hashbrowns, spreading evenly. Cover with the remaining hashbrowns and gently press into the chicken mixture. Top the casserole with the remaining shredded cheese.

Cover the dish loosely with aluminum foil and bake for 20 minutes at 375-degrees F.

Remove the foil, and continue to bake for an additional 25-30 minutes, until the casserole is bubbly, the hashbrowns are golden, and the cheese is melted. (Placing the casserole under a broiler for a few minutes will help to achieve that golden-brown color on the hashbrowns.)

Remove from the oven and let the casserole rest for 5 minutes.

Garnish with sliced green onions and fresh cilantro. Serve and enjoy!