Preheat oven to 400F. Lightly grease a 9-inch oven-safe skillet. Set aside.
In a medium bowl, combine chicken, corn, cream cheese, sour cream, green chiles, and 1/4 cup green enchilada sauce until evenly combined.
Pour about 1/2 cup enchilada sauce in the bottom of skillet. Top with 4-5 corn tortillas, 1/3 of chicken mixture, 1/2 cup enchilada sauce, and 1/3 of cheese. Repeat layers twice more ending with cheese.
Bake casserole at 375F 25-30 minutes until cheese is melted and filling is bubbly. Optionally, broil under high 1-2 minutes to brown cheese.
Allow casserole to stand 10 minutes before serving with fresh cilantro, avocado, tomatoes, and sour cream on top. Enjoy!