In a saucepan, combine balsamic vinegar and honey over medium heat.

Bring the mixture to a boil, then reduce heat to low and simmer.

Let it simmer for about 15-20 minutes, stirring occasionally, until it thickens and reduces by half.

If using cornstarch, mix it with water to create a slurry and add it to the saucepan, stirring until the glaze thickens.

Remove from heat and let it cool before using.