Combine chicken, sour cream, onion, grean chilies and 1 cup cheese. Fill each tortilla with a little bit of this mixture. Roll up and arrange seam side down in prepared pan.
Cover with enchilada sauce.
Combine chicken soup, water and remaining cheese. Pour this mixture on top of the tortillas in the pan.
Bake 35-40 minutes.
Top with lettuce, sour cream or any other desired toppings.