Mayonnaise is the Devil's Work

Double-yolk eggs = amazing mayannaise.

You will want to eat it straight from the jar, with a spoon.

This is basically Deborah Madison’s recipe from Vegetarian Cooking for Everyone, but less precise:

1 egg (double-yolked!!!!)
3/4 c. canola oil (or olive oil, but I find it too strong)
a big of Dijon mustard
salt
a dash of mild acid, like lemon juice or white wine vinegar

Put the egg, 1/4 c of the oil, the salt, and the mustard in a blender. Turn it on for about 30 seconds, until it’s opaque. Then add the rest of the oil through the top with the motor running. Add in a bit of vinegar. And you’re done.

It’s mayonnaise. We use it in sandwiches, aioli, blue cheese dressing, tuna salad, egg salad (more eggs!), potato salad. It’s hard to go wrong here unless you’re avoiding raw eggs, in which case I can only say: I’m so, so sorry.