Preheat your air fryer to 170°C.
Add the breadcrumbs and egg to two plates. Dip a piece of chicken first into the egg and then the breadcrumbs, completely coating all sides.
Repeat with the rest of the chicken, spray lightly with low-calorie cooking spray and place into the air fryer basket. Depending on the size of your air fryer you may need to split into 2 batches.
Cook for 15 minutes, turning halfway through until the nuggets are crispy and golden. To test that the chicken is cooked, cut a piece in half, checking that the juices run clear and there is no pink remaining.
While the nuggets are cooking, add the ketchup, honey, soy sauce, Henderson's relish, paprika and garlic granules to a small bowl and stir to combine.
Transfer the chicken nuggets to a large mixing bowl and pour over the sauce. Toss to coat, then add back to the air fryer and cook for a further 4-5 minutes.
Remove the chicken nuggets from the air fryer and serve with an accompaniment of your choice!