Tear chicken into bite size pieces, mix with soup, chili, salsa and tapioca. Line bottom of crock pot with 3 corn tortillas, torn into bite size pieces. Add 1/3 of the chicken mixture. Sprinkle with 1/3 of the onion and 1/3 of the grated cheese. Repeat layers of tortillas topped with chicken mixture, onions and cheese. Cover and cook on low 6 to 8 hours.
Garnish with sliced black olives.