There's a few things that are always better home made, if you have the time, this is one of them. I don't have a blender, it's quicker if you do, but this recipe assumes that you don't.
Place a new egg yolk in a clean bowl and gradually add the curdled mixture to the yolk, whisking constantly as you do it. Then add the rest of the oil, drop by drop.
This turned out nothing like mayonnaise for me. It looked like mustard. It was bright yellow from the egg yolk. Maybe I wasn't vigorous enough with my hand mixing? It also tasted very strongly of olive oil. It really needs to be blended and a milder tasting oil used. Sorry, but I won't be making this one again. - 09 May 2013