Wash and soak the chickpeas and black soybeans thoroughly.
Place the soaked beans in a pot with plenty of water and boil them until cooked.
Drain the boiled beans and let them cool.
Add the cooked beans, water, and salt into a blender and blend until smooth.
Strain the blended mixture using a sieve or cheesecloth to extract the soy milk.
Pour the strained soy milk into a pot and simmer over medium-low heat, stirring continuously.
After it is gently boiled, cool it down and pour into cups to serve.