Heat olive oil in a large skillet. Season chicken with salt and pepper to taste. Add to skillet, cover and cook for 20 minutes or until juices run clear, flipping over after 10 minutes. Remove from skillet and shred.
Add onion to the skillet and cook for 5 minutes. Stir in flour and cook 2 more minutes, stirring often. Whisk in chicken stock, bring to a boil and let simmer until thickened.
Remove skillet from heat. Stir in sour cream, green chilies and seasonings. Reserve 1 c. sauce. Stir chicken into skillet and fill tortillas with about 2 T. filling, roll up. Place rolled up enchiladas in a greased casserole dish. Cover with reserved sauce.
Bake at 350 degrees for 30 minutes. After the first 15 minutes, sprinkle 1 c. cheese over the top and return to the oven.
