01 - Arrange the chicken breasts or thighs in an even layer at the bottom of the slow cooker insert.
02 - Sprinkle the taco seasoning, smoked paprika, salt, and black pepper evenly over the chicken pieces.
03 - Pour the salsa and chicken broth (or water) over the seasoned chicken. Squeeze fresh lime juice directly into the cooker.
04 - Cover with the lid and cook on high setting for 4 hours or low setting for 7 hours, until the chicken reaches internal temperature of 165°F and shreds easily.
05 - Transfer the cooked chicken to a clean cutting board or large bowl. Using two forks, pull the meat apart into shredded pieces.
06 - Return the shredded chicken to the slow cooker and stir thoroughly to ensure all pieces are well-coated in the cooking juices.
07 - Heat the taco shells according to package directions—either in a dry skillet for corn tortillas or oven for crispy shells.
08 - Fill each warmed shell with a generous portion of shredded chicken. Top with lettuce, cheese, sour cream, tomatoes, red onion, avocado slices, cilantro, and a squeeze of fresh lime. Serve immediately.