In a large mixing bowl combine the diced chicken, diced onion, minced garlic, olive oil, curry powder, ground ginger, and salt; toss until the chicken is evenly coated.
Marinate the seasoned chicken mixture for 30 minutes at room temperature.
Transfer the marinated chicken and onion into an air fryer–safe pan or dish that fits your air fryer basket in a single layer as much as possible.
Set the air fryer to 400°F and cook the chicken for 15 minutes, shaking or stirring once halfway through for even cooking.
Carefully remove the pan from the air fryer and pour the cooked chicken and any juices into a heatproof mixing bowl.
Add the heavy cream and the cornstarch slurry (1 tsp cornstarch mixed with 2 tsp water) to the bowl and stir to combine into a creamy sauce.
Return the mixture to the air fryer pan, place it back in the air fryer basket, and cook at 400°F for an additional 7 minutes to thicken the sauce and finish cooking the chicken.
Remove from the air fryer, garnish with chopped cilantro, and serve.