Place everything in a tall cup or beaker that came with your immersion blender.

Make sure your immersion blender catches the egg yolk in the blade at the bottom.

Turn it on and hold it still at the bottom for 30 seconds to a minute—until it thickens and starts to sound like it’s working harder.

Once it starts thickening, slowly move the blender up and down to incorporate the oil from the top.

Blend until it’s fully combined and creamy.

That’s it. It thickens like magic when you do it this way!