Start by placing the boneless, skinless chicken breasts into your slow cooker. Sprinkle them generously with adobo seasoning, garlic powder, and ground cumin.
Pour the chunky salsa over the seasoned chicken.
Cover the slow cooker and set it to low for 6-8 hours or high for 3-4 hours.
Once the chicken is cooked, use tongs to remove it from the slow cooker. Shred the chicken in a bowl, then return it to the slow cooker, mixing it with the juices.
While the chicken is cooking, prepare your toppings: shred the red cabbage, chop the cilantro, and slice the avocado.
Warm the corn tortillas in a skillet or microwave. Layer the shredded chicken on each tortilla, then top with shredded cabbage, a squeeze of lime juice, chopped cilantro, and sliced avocado.