Place chicken breasts in slow cooker. Season with salt, pepper, and chili powder.
Pour enchilada sauce over the top and cook on high for 4 hours or low for 6-8 hours.
Shred chicken with two forks.
Cut tortillas in half, then into large strips, and stir into chicken and sauce.
Add ⅓ of the cheese and stir once more. Press mixture down with the back of a spoon.
Top with remaining cheese and as many olives as you'd like. Cover and cook on low 45 minutes more, or until cheese has melted.
Serve with sour cream and green onions, if desired. Enjoy!
