Slice the chicken breast into thin strips and season with the sea salt, black pepper, and garlic powder.
Heat the olive oil in a skillet over medium-high heat and sauté the chicken until golden brown and cooked through, about 6-8 minutes.
While the chicken cooks, finely shred the green cabbage and place it in a large mixing bowl.
In a small blender or food processor, combine the avocado, Greek yogurt, lemon juice, parsley, and chives, blending until completely smooth.
Pour the avocado dressing over the shredded cabbage and toss thoroughly to coat every piece of slaw.
Transfer the slaw to a serving plate, top with the warm sautéed chicken, and sprinkle with pepitas for added crunch.