Preheat oven to 350 degrees F. For the enchilada sauce: in a medium bowl, whisk together ½ cup of sour cream, chicken broth, and 1 can of red enchilada sauce until creamy and smooth--set aside.
In a large bowl, mix together the chicken, onion, garlic powder, pepper, salt, ½ of the jack cheese, a ¼ of the cheddar cheese ¼ cup of enchilada sauce from step 1, and ¼ cup of green onions. Mix until all ingredients are combine.
In a 13” x 9” glass baking dish, spread the enchilada sauce to coast the bottom of the baking dish. Get a torilla and fill each tortilla with about 1/3 cup of the chicken filling, then sprinkle more cheese inside—this is completely up to you of how much cheese you want but we love cheese in our enchiladas! You can totally omit these cheese in this step if you prefer. Roll the each tortilla and place on the baking dish.
Top the tortillas with more enchiladas sauce until coated, then sprinkle more cheese and green onions on top. Cover with foil and bake for 20 minutes or until cheese is melted. Top with sliced avocados and sour cream!