Preheat oven to 350 degrees. Butter or grease an 8x8 pan and set aside.
Melt butter in a medium skillet over medium-high heat. Add the celery and onions. Cook for 5-7 minutes or until tender. Turn down heat to medium and add cream to the pan and stir constantly and reduce by half, until thick and creamy and set aside.
In a large bowl combine the chicken, ½ cup of each cheese, chiles, sour cream, veggie mixture, and seasonings and stir till incorporated. Spread the mixture evenly in the prepared pan and top with the remaining cheese.