In a large bowl, combine the chicken with half of the spices (paprika, cumin, oregano, and garlic powder), lemon juice, olive oil, salt, and pepper. Toss until everything is evenly coated.
Add the vegetables to the bowl along with the remaining spices and toss again so everything is well seasoned. If you have time, let it marinate for 15–30 minutes—it’s optional, but it really boosts the flavor.
Preheat the air fryer to 375°F (190°C).
Arrange the chicken and vegetables in the basket in a loose, even layer. Work in batches if needed so nothing overlaps too much.
Air fry for 25–30 minutes, shaking halfway through, until the chicken is cooked through and the edges are lightly charred.
While everything cooks, stir together the parsley, olive oil, lemon juice, garlic, oregano, chili flakes, salt, and pepper to make the chimichurri. Let it sit for 5–10 minutes so the flavors can develop.
Plate the hot chicken and vegetables and spoon the chimichurri generously over the top before serving.