Try these suggested additions for depth of flavor: 1) Add 1 teaspoon freshly cracked black pepper to the mixture before cooking. 2) Scrape the seeds and add the pod of 1 whole vanilla bean, split lengthwise, into the mixture before cooking (remove the pod before storing). Or use 2 teaspoons vanilla-bean paste. 3) Add 2 tablespoons balsamic vinegar to the mixture just before removing from the heat.