Add the chicken to the bottom of your slow cooker. I used 3 good sized chicken breasts.
Pour over the salsa. Cover and cook on Low setting for 6 to 7 hours, check at 6 hours and if tender and shreds with a fork at this point, continue with the next step, if not tender, continue to cook and check at 7 hours. I used the Fast and Simple Fresh Salsa II listed on this site, excellent salsa which makes just a tad over 2 cups, use all of it.
Plop the cream cheese on top of the chicken. Cover for about 10 minutes to let it get really soft. While the cheese is softening, shred the Cheddar cheese and cut up the tortillas into strips, and slice the olives.
With the cream cheese softened, shred the chicken with 2 forks right in the slow cooker and stir together.
Add the tortilla strips, 1 cup of Cheddar cheese, and half of the olives and stir this into the chicken mixture. Flatten this down and clean the sides of the pot.
Add to the top the remaining cheese then olives. Cover and cook on High setting for another 45 minutes until the casserole is heated through.