Add the chicken to a bowl, along with the pesto and lemon juice. Stir the chicken until fully coated, then cover the bowl and pop it in the fridge for 30 minutes.
Add the breadcrumbs to a plate. Remove the chicken from the fridge and dip each chicken piece into the breadcrumbs - completely coating them on all sides. Then place onto a plate.
Repeat this process with the rest of the chicken, then place into the air fryer basket. Spray with low calorie cooking spray.
Cook at 170ºC for 15 minutes - until the nuggets are crispy and golden. To test that the chicken is fully cooked, cut a piece in half - the juices should run clear, and there should be no sign of pink remaining.
In a small bowl, combine the mayonnaise, yoghurt, lemon juice, and garlic - then give it a good stir. Season to taste, and serve alongside the nuggets.