Preheat BBQ to high, or your oven to maximum temperature.
Peel the red onions, removing the top stem and the root from each piece. Cut an incision in the outer three layers of each peeled onion from top to bottom. Carefully remove the onion shells and set aside to wrap meatballs. Finely dice the centre of the onion.
To make the meatball mixture, combine chicken mince, mushroom mince, diced onion centres, chives and garlic in a large mixing bowl.
Season with the BBQ and Worcestershire sauces, mustard, grated apple, salt and pepper.
Add the eggs and the breadcrumbs, mixing until evenly combined. Add more breadcrumbs if mixture is too sticky to shape.
Shape the meatball mixture into golf ball sized balls, stuffing each with one cherry bocconcini.
Wrap each meatball in the onion shell and wrap with a couple of slices of pancetta/bacon. Secure with a toothpick.
Cook the chicken bombs until well browned all over, around 2 minutes each side. Baste with BBQ sauce and close the BBQ hood to cook the meatballs through, approximately 10 minutes. If using the oven, cook for 20 minutes on 180c
Serve on a plate, or use a paddlepop stick or toothpicks to make meatball lollipops.