How to make your own Mayo:
(1 cup)
1 egg yolk
2 teaspoons Dijon mustard
1 cup good-quality olive oil (not extra-virgin)*
Salt and pepper
1 tablespoon fresh lemon juice
Substitutions
Oil --> avocado oil
Acid --> white wine vinegar or sherry vinegar
1. MACHINE: Put yolk and mustard in a blender or food processor and turn the machine on. While it’s running, add the oil in a slow, steady stream. When an emulsion forms, you can add it a little faster (and scrape down the sides as necessary), until all the oil is incorporated.
1. HAND: Put yolk and mustard in a medium bowl. Beat together with a whisk. Begin to add the oil in dribbles as you beat, adding more as each amount is incorporated.
You’ll notice when a thick emulsion forms. Then you can add the remaining oil a little faster.