For the marinade, grate the ginger and garlic along with a tablespoon of soy sauce and add to the buttermilk. Add the chicken to the marinade. Marinate in the refrigerator for at least 2 hours.
Mix the panko and sesame seeds in a deep dish. Dip the chicken pieces, one at a time, through the panko, shaking off excess.
Then dip them back into the marinade and through the panko again. Coat the chicken nuggets with a little olive oil and place in the air fryer. Keep them in a single layer or they won't get crispy.
Bake the chicken nuggets at 180˚C for 15 minutes or until golden brown, turning once halfway through.
Meanwhile, make the dip. Stir the hoisin and soy sauce into the mayo. Slice the spring onion into thin rings and sprinkle over the golden brown chicken nuggets. Delicious with a squeeze of lime juice.