Heat the vinegar in a small saucepan over medium heat. Once it begins to boil, turn down to medium-low or low. Simmer uncovered for about 10 minutes, or until reduced by half.
Remove from heat for a moment while you stir in the honey.
Return to heat and simmer another 1-2 minutes until thickened to the consistency of chocolate syrup.
Cool about 5 minutes, if desired. It will continue to thicken as it cools.