Preheat oven to 350 degrees Fahrenheit. Spray a 9x13 inch casserole pan with avocado oil.
Over medium heat sauté onion with 1 tbsp avocado oil and cook until tender. Shred 3 cups of rotisserie chicken and place in bowl. Grate cheddar, mozzarella and pepperjack cheese. Set aside.
Add to your chicken, sour cream, green chiles, sauteed onions, half the cheese mixture, 1/4 cup red enchilada sauce and 1/4 cup green enchilada sauce, dash of salt and pepper. Mix until well combined.
Fill each tortilla with filling mixture about 1/3 cup each. I like to roll my enchiladas like a taquito (not a burrito) and leave the sides open. Place the tortilla seam side down in the pan. Filling the entire pan full.
Pour over the remaining red sauce on one half of the pan and on the other half pour over the remaining green sauce. Sprinkle with remaining cheese.
Cover with foil and bake in oven for 30-40 minutes. Remove foil for the last 10 minutes of cooking. Bake until cheese is melted, and enchiladas sauce is bubbling. Top with desired toppings and serve.