I usually buy balsamic glaze from Trader Joe's (not sponsored). If you don't have a store bought one, you can make it on your own. Simply pour 2 cups of balsamic vinegar into a sauce pan and put on the stove over medium/high heat. As soon as it starts to simmer, reduce the heat to low and let it cook for about 20 minutes or until the it thickens and reduces to 1/2 cup.