Remove the membrane on the bone side of the rib joint. Do this by simply sliding a sharp knife under a corner to release the membrane, then pulling it away. If you are lucky, it will come off in one piece!
Mix together the ingredients for the dry rub, massage them into the ribs and set aside for anywhere between 8 and 24 hours to marinade.
If you are using the trivet that came with your Instant Pot, raise it off the base by a couple of centimetres (¾") using a crockery pot.
Cut your side of ribs so that they will fit in the Instant Pot. I usually cook them standing up and curl them around the side of the pot, which means there is minimal cutting.
Peel the onion and cut it into 8 wedges.
Pour the apple juice into the base of the pot, followed by the onions and finally the ribs, close the lid and cook on manual high pressure for 20 minutes.
Preheat your oven to 220°C or 430°F. Do this to coincide with the ribs being ready to come out of the Instant Pot
Remove your ribs carefully from the pot and set aside whilst we work on the glaze.
Take out the trivet and the pot you used to raise the height of the trivet. Turn the Instant Pot on to saute mode, add in the onions, honey and mustard and reduce to form a syrupy glaze. This should take 5-10 minutes, then blend with a stick blender.
Finally, pour the glaze over the ribs, transfer them to the hot oven and get a nice glaze which should take 5-10 minutes, or even better, finish on the BBQ.