To make by hand, use a wire whisk to beat together the egg yolk, mustard, and ginger in a bowl. Combine the oils. Begin to add the oil VERY SLOWLY, a little at a time (otherwise it won’t thicken)
as you beat, adding more as each bit is incorporated. Once a thick emulsion forms – you’ll know it – you can add the oil a little faster. Depending on how fast you beat, the whole process should take 2-5 minutes.
To make by machine, put the egg yolk, mustard and ginger in the container of a blender or food processor and turn on the machine. While it’s running, add the oils in a VERY SLOW steady stream. Once an emulsion forms, you can add the oil a little faster. Transfer to a bowl.
Add the soy sauce, lime juice, chile, and sesame seeds and stir.