In a small bowl, mix together the chipotle chili powder, cumin, garlic powder, onion powder, smoked paprika, salt, and black pepper to create a spice rub.
Pat the chicken breasts dry with paper towels and rub the spice mixture evenly onto both sides of each chicken breast.
In a large skillet, heat olive oil over medium-high heat. Add the seasoned chicken breasts and cook for about 5-7 minutes on each side, or until the chicken is cooked through (internal temperature of 165°F).
Once cooked, remove the chicken from the skillet and let it rest for a few minutes. Then slice the chicken into thin strips.
While the chicken is resting, warm the corn tortillas in a dry skillet over medium heat for about 30 seconds on each side until soft and pliable.
To assemble the tacos, place a few strips of chicken onto each warmed tortilla. Top with shredded cabbage, fresh cilantro, avocado slices, and a generous spoonful of salsa or pico de gallo.
Squeeze fresh lime juice over the top for an extra zing.