Place oil and purple onion in a pot on low heat and simmer until just golden
Remove onion from oil and onto a paper towel lined plate. Season with salt and save for later.
Pour 350mls of onion oil into a jug and set aside to cool
Place, egg yolks, egg, fish sauce, sugar and salt into a stick blender canister
Gently pour the cooled onion oil into the same canister and and blend while slowly, moving the stick up and down until smooth and pale
Place Mayo/Bo into a container
Slather onto anything and everything
