Combine the chopped onion, soups, green chiles, chicken stock and salt and pepper to taste in a saucepan. Cook for 15 to 20 minutes until the onions are soft. You don’t sauté the onions first. After the onions are soft add the chicken, stir to combine and set aside.
Preheat the oven to 350 degrees F. Get your casserole dish, sauce, cheese and tortillas together to start layering.
In a 9x11 casserole or pan put a thin layer of the sauce on the bottom. Top with 6 tortillas (they’ll overlap a little).
Top with a layer of sauce.
Add a layer of cheese, a little sauce, then top with 6 more tortillas.
Add the remaining sauce and cheese.
Cover with foil that you have sprayed or rubbed a little oil on so it won't stick to your cheese. Bake for 30 minutes, then remove the foil and cook about 10 minutes longer.
Serve with pinto beans or refried beans, Mexican rice or even a nice salad and tortilla chips.
