It’s really important the milk and the oil are at the same temperature, that way the mayonnaise is easier to make.
Use an immersion blender to combine all the ingredients in the blender cup, place the immersion blender in, so that way it sits firmly on the bottom of the cup and pulse until the mayonnaise emulsify. Once most of the vegan mayo has emulsified, you can move the blender up and down to incorporate any oil that is sitting on the top.
Try the mayonnaise and add more salt if needed. If it’s too thick, add more milk and if is too watery add more oil. Pulse again until the mayonnaise has the perfect consistency.