Combine all ingredients in a small blender or food processor. Blend for 30–60 seconds, or until completely smooth. Store in an airtight container in the fridge for up to one week.
Notes
I typically roast my own beets for this (I’ll roast a whole bunch and use the other beets for something else), but if you don’t feel like spending an hour roasting a beet, you can find pre-cooked beets at most grocery stores. Look for them in vacuum-sealed packages in the refrigerated section of the produce department.