1. Put the 2 tablespoons of Fat Free Mayo and the mustard into a container and blend with a fork. Add 2 tablespoons of water and blend again.
2. It may seem runny at first, but just stir a little more - the mayo, since it is fat-free, will emulsify with water instead of oil! Add more or less mustard, water or mayo until you get a consistency and flavor you like. You can certainly also make a bigger batch. I use more like 6T of mayo, 3 tsp of mustard and add water in increments until it is runny enough.