Preheat oven to 350º
In large skillet saute onions until soft and browned.
Add chopped jalapeño pepper and cook an additional 2 minutes.
Blend together all the shredded cheese.
Shred cooked chicken and place in large bowl.
Stir in onions and jalapeño pepper.
Toss ½ of cheese mixture with chicken.
Stir in ½ cup Enchilada sauce.
Spread ½ cup enchilada sauce bottom of 9x13 baking pan.
Lay out tortillas and fill with chicken mixture, dividing mixture equally.
Roll tortillas and place tortillas seam side down in baking pan.
Spread remaining Enchilada sauce over tortillas.
Sprinkle with remaining cheese.
Bake 20 to 30 minutes until bubbly.
Garnish as desired with fresh avocado, green onion, chopped tomatoes, peppers