Put 3 to 4 tablespoons of chicken stock in a 9 x 13 inch baking dish. Add a layer of tortilla strips, and then a layer of chicken. Pour soup mixture over chicken and tortillas. Continue to layer in this order until dish is full. Top with cheese. Cover and refrigerate for 24 hours.
Bake at 300 degrees F (150 degrees C) for 1 to 1 1/2 hours.