White Chicken Enchilada Casserole

boneless, skinless chicken breasts or thighs, cooked and shredded (rotisserie works well, too)

medium onion, grated

salsa verde (green)

lowfat cream of chicken soup

lowfat cream of mushroom soup

milk

garlic powder

freshly ground black pepper

corn tortillas

grated sharp cheddar cheese

Sliced olives for garnish