Step 1

Pulse the egg, mustard, vinegar, and water: In a blender or food processor, combine the egg, mustard, vinegar, and water (if using). Pulse a few times so it’s mixed but not aerated.

Step 2

While the machine is on, slowly pour in the oil: Have the oil ready in a glass measuring cup. Turn on the blender or food processor and add the oil in a thin stream (if you are using a food processor, the food tube insert will dribble it in for you).At first it will look like a yellow disaster, but press on. Soon you’ll have a pearly, creamy mixture that gets thicker the more oil you add.

Step 3

Scrape out the mayonnaise and season: Once all the oil is added, turn off the machine and scrape out the mayonnaise. Season to taste with salt and optional Tabasco. (I like to taste the mayonnaise on a carrot stick or piece of lettuce to get a better idea of what it’ll be like on other food, which is how you will eat it.)Store, tightly covered, in the refrigerator for up to one week.