Add the egg, salt, mirin, dijon mustard, rice wine vinegar and ¼ of the vegetable oil into the bullet blender cup. Place the lid on tight, then pop on the base and blend for 10 seconds.
1 egg, 1 tbsp rice wine vinegar, 1 tbsp mirin, 1 tbsp dashi stock, 1 tsp dijon mustard, ¾ tsp salt, 100 ml vegetable oil