Add the dried chickpeas to a grain mill and set to fine setting. Turn on the machine to get the finely ground chickpea flour.
If using a high-powered blender, add the chickpeas and turn on. Increase the speed to the machine's maximum. Blend until the chickpeas have ground as finely as possible.
Using a fine mesh sieve, sift the flour into a bowl to separate any large bits. Return these hard bits back to the blender and process again. You may need to repeat this step to get all pieces finely ground.