1/4 teaspoon freshly ground black pepper (or peppercorn medley)
Directions
Dump all ingredients into a appropriate sized mixing bowl and whisk until smooth.
This is a sauce that works best if you adjust sour cream and mayo to your liking. I typically like a bit more bias towards mayo and a bit heavier on the horseradish.
Place in the fridge for at ~ 4 hours (or overnight) to allow flavors to meld.
Store refrigerated, in airtight container for 2-3 weeks