Cheesy Chicken Green Chile CASSEROLE

4 whole chicken breasts
1 onion, chopped
1 large can of cream of chicken soup
5-6 large green chile More or less depends on how much you love them
1 lb grated cheese (Jack, Cheddar, sharp)
24-30 small corn tortillas ( I soften mine ahead of time )

Poach chicken breasts with chopped onion until cooked, about 15 minutes. When cool, shred into small pieces and chop the cooked onion and place chicken and chiles into a bowl with the can of soup AND some of the poaching liquid. (You can do this the night before or have it ready.)
Spread a ladle full of the chicken green chili mix on the bottom of a 3 quart casserole pan . Cover with a layer of tortillas and a layer of chicken , followed by a layer of shredded cheese. Repeat until you have used all the ingredients and you end up with a final layer of cheese on the top.

Bake in a 325°F oven until bubbly...let it set a few min before serving