Bring the eggs to room temperature before separating the yolks & whites.
Add the yolks to a mason jar along with a splash of rice vinegar, the juice of ½ a lemon, a heaping tsp of dijon mustard, and pinches of salt, MSG, and sugar.
Add just over a cup of neutral oil (avocado or similar) to the jar, then use an immersion blender to whip until smooth and creamy— about a minute or so.
Use immediately, or store in an airtight container in the fridge up to a week.
