Dice the chicken breast into small, bite-sized pieces.
In a small bowl, combine the ground cumin, chili powder, garlic powder, sea salt, and black pepper.
Toss the chicken pieces with the spice blend until every piece is evenly coated.
Heat the olive oil in a non-stick skillet over medium-high heat and sauté the chicken until golden brown and cooked through.
While the chicken cooks, mash the avocado with the Greek yogurt and lime juice in a small bowl until the crema is smooth and silky.
Warm the corn tortillas in a dry pan over medium heat for 30 seconds per side until pliable.
Assemble the tacos by layering the spiced chicken, shredded cabbage, diced red onion, and fresh cilantro onto the warm tortillas.
Drizzle the avocado crema over the top and serve immediately.