To make King Ranch casserole, cook chicken, onions, spices, creamed soup and tomatoes in a skillet, and layer the cooked chicken mixture with cheese and corn tortillas in a baking pan. Bake the dish for 30 minutes at 350 degrees Fahrenheit.
Saute one chopped onion and one chopped bell pepper in 2 tablespoons of oil in a skillet on medium-high heat, and add 2 cups of cooked, diced chicken to the mixture. Continue cooking, and add one 10 3/4-ounce can each of cream of chicken and cream of mushroom soup and one 10-ounce can of tomatoes with diced green chiles. Stir in 1 teaspoon of chili powder and 1/4 teaspoon each of salt, garlic powder and black pepper.
Tear 12 corn tortillas into 1-inch strips. Place 1/3 of the tortillas in the bottom of a greased 13- by 9-inch baking pan, top with 1/3 of the chicken mixture, and sprinkle 2/3 cup of cheddar cheese on top of the chicken. Continue layering the tortillas, chicken and cheese, and bake the casserole at 350 degrees Fahrenheit for 30 to 35 minutes.
Alternately, mix one bag of frozen onion, bell pepper, celery and parsley into a bowl with the cooked chicken, add the spices, soups and tomatoes, and layer the mixture with the cheese and tortilla strips. Bake the casserole at 350 degrees Fahrenheit for 35 minutes.