Chicken Enchilada Casserole

This is my go-to, gotta make something the whole family will eat meal. It's easy and the prep time isn't too bad considering it cooks inself in the crockpot after that.
Bob requests this for his birthday and Father's Day and any other day he thinks he should get a special meal.

You need:
3-4 lb chicken, I use a whole cut up chicken, you can also use half breasts with the bones still in.
1 medium onion, chopped
1 Tbsp. oil
1 can of cream of mushroom soup
1 can of cream of chicken soup
(I use the reduced fat, sodium kind, no taste difference)
1 cup sour cream
1 - 28 oz can green enchilada sauce
1 - 4.5 oz can peeled diced green chiles
20 corn tortillas
3 cups shredded cheddar cheese

Prep:
Boil chicken. Shred meat and discard bones and skin. (I freeze the broth from this in ice cube trays for use later as chicken stock) You can do this step a day ahead and keep the chicken in the fridge until you're ready to whip up the sauce and assemble.

Sauce:
Saute onion in oil in saucepan until translucent. Add can of green chiles cook one more minute. Stir in soups, sour cream and enchilada sauce. Warm through.

Cut the tortillas into four wedges. I do this in a big stack rather than one at a time!

Assemble:
In your crock pot, layer sauce, chicken, tortillas and cheese, it's usually three or four layers, end with cheese then pour the remaining sauce all over the top.

Cover. Cook on low 5-6 hours or high 2-3 hours (I recommend slow!)