Now, add the shiro powder, along with salt and 3 cups of water, and bring to a boil on medium heat. Then, turn down the heat to a low to medium, and let it simmer for about 20 to 30 minutes to allow the mixture to thicken to your desired consistency. Stir at 5 minute increments to ensure it doesn't stick. The oil will float to the top when the shiro is done cooking! Taste and adjust salt and serve hot with rice or injera!