If you'd like to make your own balsamic glaze, it's super easy and only requires 1 ingredient. Heat 1 cup of balsamic vinegar in a small saucepan over medium heat. Bring the vinegar to a boil, then reduce the heat to low and let it simmer until it's reduced by half and has a syrupy consistency. This will take about 20-30 minutes. Let the glaze cool before using it on the appetizers.