This balsamic and mustard vinaigrette takes less than 5 minutes to prepare, and it makes a fabulous dressing for almost any tossed salad. The balsamic vinegar gives the vinaigrette a sweetness, while the mustard adds a spicy, pungent flavor. When you dress a salad, use just enough to highlight and flavor; don't add too much vinaigrette or the lettuce will be soggy and the ingredients will be overpowered by the dressing.