Place potatoes, corn, celery, carrots, onion and garlic in slow cooker. Stir in salsa, salt, cumin, chile powder and pepper. Distribute chicken evenly on top of vegetables and pour chicken broth over chicken. Cover slow cooker and cook stew on high for 4 hours.
Transfer chicken to a plate and shred with two forks into bite-size chunks; return to slow cooker. Mix tortilla strips into stew. Serve warm.