Combine soup, onions, chile peppers, milk and 2/3 cup of the cheese in a bowl and mix.
Place crushed tortilla chips onto the bottom of a casserole dish. Then add 1/2 the chicken and 1/2 the sauce.
Add another layer of chips, chicken and sauce into casserole dish.
Add remaining tortilla chips and 1/3 cup of cheese.
Bake in oven at 350* for 30 minutes.