Mix together and refrigerate at least 2 hours or overnight. (you can simply stir together but oftentimes I'll use my chopper to blend it quickly and easily.)
Notes
Horseradish:
I use the refrigerated jarred variety - It's usually listed as "Prepared Horseradish" (not the "creamed" variety or the purple one with cabbage.) I generally find it either in the dairy section or the seafood section. I typically buy Kelchner's or Gold's brand - may be regional.
Nutrition (approx. data estimated via online nutritional calculator.)