Preheat your air fryer to 400°F.
Cut the chicken breast into uniform 1-inch cubes and pat them dry with a paper towel.
In a medium bowl, whisk together the arrowroot starch, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Add the chicken cubes to the bowl and toss thoroughly until each piece is evenly coated in the spice mixture.
Lightly mist the chicken with avocado oil spray or toss with the half teaspoon of oil to ensure a golden finish.
Place the chicken in the air fryer basket in a single layer, ensuring they are not touching for maximum airflow.
Air fry for 8 to 10 minutes, shaking the basket halfway through, until the chicken is cooked through and the edges are golden.
While the chicken cooks, whisk together the Greek yogurt, Dijon mustard, and lemon juice in a small ramekin until smooth.
Serve the warm chicken bites immediately with the zesty dipping sauce on the side.