About 30 minutes from the end of cooking, lift the pork from the stew, and slice off the rind. Return the pork to the pot.
Line a grill pan with foil, and pour on to it about a tbsp of oil. Pat dry the pork rinds (which will be sticky). Toss them in the oil in the pan, and arrange skin-side up. Grill them at full setting at first, but turn down the heat as soon as they start to make crackling noises. The danger is, if you keep them too close to a high flame, that they will burn before turning crisp. I move the pan down to the floor of the grill.
The process will probably take about 15 to 20 minutes.