Add all ingredients to a small glass jar that's just wide enough for the head of the immersion blender (a 1 pint Mason jar works perfectly). Let them sit for a few seconds until the egg has settled at the bottom of the jar.

Insert the immersion blender all the way to the bottom of the jar.

Turn the power button on and leave the immersion blender exactly where it is for at least 30 seconds. You should begin to see the magic of emulsification taking place right before your eyes.

After 30 seconds most of the oil should be incorporated, but you can move the blender around a bit to make sure every last bit is mixed in. If for some reason your mayo does not emulsify you can either try to rescue it by essentially starting over with another egg yolk (just google it!) or turn it into Ranch dressing. But hopefully it turns out beautiful and creamy and delicious every time!