Dice the chicken breast into small, bite-sized pieces.
In a small bowl, combine the chili powder, cumin, garlic powder, sea salt, and black pepper.
Toss the chicken in the spice blend until evenly coated.
Heat the avocado oil in a large skillet over medium-high heat.
Add the chicken to the skillet and sauté for 6-8 minutes until golden brown and cooked through.
While the chicken cooks, finely dice the white onion and chop the fresh cilantro.
Slice the avocado into thin wedges.
Warm the corn tortillas in a dry pan or over an open flame for 30 seconds per side until pliable.
Divide the chicken evenly among the three tortillas.
Top with diced onion, cilantro, and avocado slices.
Squeeze fresh lime juice over the top before serving.