Select a 2-3 cup container with tall sides, and check to make sure it’ll fit the head of your stick blender.
Once you’ve confirmed that it does, crack in the egg and add the vinegars, salt, and paprika.
Without stirring, pour all of the oil directly on top, then leave the mixture alone for about 30 seconds so it can fully separate.
Stick the head of your stick blender right in so it rests on the bottom of the container.
Let the mixture settle again, just for a few seconds this time—you want the oil and liquid to be totally separated until the second you start up the blender.
Keeping the blender totally still, turn on the power.
Don’t move the blender at all for at least ten seconds: the vortex created by the blades will gradually pull oil down into the liquid, emulsifying all on its own.
When the bottom part of the mayo thickens and turns pale yellow, slowly rock the blender from side to side to introduce more oil into the emulsion.
Finally, pull the blender up and down like you’re making a puréed soup, until all the oil is incorporated and the mayo is thick and creamy.
Tap and scrape whatever’s on the blades back into the container, give everything a stir, and have a taste: it should be creamy, super-tangy and well salted.
If you think the balance is off, gradually stir in small amounts oil, vinegar, or salt to taste.
