1. Put it all into a clear container, and place a stick blender into the container. The container should be jar-like, making a tight fit for the blender to fit into without too much space either side of the blender.
2. Let it settle for a moment before you start to blend, just hold it there, quite still.
3. Start the blender, and keep it at the bottom for 20 seconds blending and then slowly move up to the top of the jar.
4. When you get to the top make sure all oil is incorporated, and switch off.
Now you have a mayo that will keep for a week in the fridge.