Add the water from the tin of chickpeas to a jug which is slightly larger than your stick blender
Add a couple of teaspoons of chickpeas (about 12)
Add in the lemon juice, mustard and salt
Blend together until smooth
While blending at a medium speed, slowly add in the oil
A thick emulsion should form
Keep blending, making sure all the oil is in the emulsion
Transfer to a clean jar, and it will keep in the fridge for a couple of weeks
