Put everything but oil in a clean old jar with a good tight lid (like an old salsa jar). Have oil measured and standing by in measuring cup with pouring lip.

Insert stick blender all the way down to the bottom of the jar. Blend egg yolks with the seasonings.

Keep blender running. Now slowly start pouring in oil; you want a stream about the diameter of a pencil lead. Work the blender up and down in the jar as you go.

When you can’t get any more oil to incorporate, and it’s puddling on the surface, stop. You’re done. Any leftover oil can go back in the bottle. Cap your jar of mayo and stash it in the fridge. (Lasts one week to 10 days.)