Preheat the air fryer to 180C.
In the bowl of the air fryer ( if your air fryer has only a basket, use a cake tin or a ceramic oven dish.), place the rice in the air fryer bowl and add the butter, red onion, garlic, lemon slices, and green chillies. Season with salt and pepper. Stir in the stock and then add in the cream and feta pieces.
Brush some mustard on the chicken. Season the chicken with salt and pepper and carefully place over the rice mixture.
Cover loosely with a layer of tin foil and a rack of the air fryer to ensure the foil does not lift up into the fan when cooking.
Close the lid over the air fryer and cook for 20-30 minutes, Check if the chicken is fully cooked and the rice is plump. if not, cook a further 5-10 minutes until the rice is cooked if needed.
then remove the rack and the foil and air fryer for 5 minutes more to allow the chicken and the top of the rice to crisp up slightly.
Remove the bowl from the air fryer, sprinkle the scallions and fresh parsley, and serve immediately while piping hot.