Prepare the chicken: Season the chicken to your liking and set aside. (Note: To save time- You can buy a cooked rotisserie chicken and just Shred it instead.)
Next, to a skillet add the oil and allow it to get hot. Add the seasoned chicken and sear on both sides until browned.
Add the chicken broth & allow the liquid to come to a boil. Lower the heat, cover with a lid, and simmer for 20 to 25 minutes.
Once the chicken is fully cooked through, remove from pan and shred the chicken. Reserve some of the chicken broth for later (About 1 to 1 1/2 Cup).
Next, in a skillet add some oil and sauté the diced onion for a minute or two. Add the cooked shredded chicken, taco seasoning, a little bit of the chicken broth, green Chiles, and salsa verde- mix everything together. Then set aside.
Warm up the tortillas for a few seconds then set aside, (you can warm them up in the microwave).
Prepare the cheese sauce: In a pot, melt the butter and add the cornstarch or flour. Mix until the flour dissolves, then pour in the reserved chicken broth. (don’t allow the mixture to boil)
Add the sour cream, green chilis, taco seasoning, shredded cheese, and whisk everything together until the cheese melts. Do a test taste, adjust cheese sauce if needed.
Preheat oven to 350 degrees. Prepare a greased baking dish and add some of the cheese sauce to the bottom of the pan.
Prepare the enchiladas: To the tortillas- add the chicken mixture, a little shredded cheese, and roll the tortillas up. Add to baking pan and repeat process until all tortillas are filled and line up the baking dish.
Next, Coat the tortillas with the cheesy enchilada sauce. Optional: Add more shredded cheese to the top layer.
Bake in the oven for 20 to 25 minutes. Then remove from oven once done.
Serve with Mexican rice, refried beans, and/or a salad. Enjoy!