As a paladin you have Hand Of Reck. which is used to taunt mobs and deal damage.
This trick is used for solo levelling/questing mainly i suppose, seeing as the spell is a taunt, and this may work for other stuns than HoJ.
You also have hammer of justice, when HoJ ends, the mob loses (or makes the server check) target for a moment.
This means for 0.5 secs or so, the mob will not have a target, thus you can use HoR to deal damage during this small gap.
Interestingly, it also gets misspelt (or so it seems) in the combat log when used like this — “Hand of Rekoning.”
So, in summation, Stun a mob, as the stun ends, very quickly hit HoR and the damage component of the spell will work as well as the taunt.