Combine chicken, brown onions, ground white pepper, cilantro roots, ginger, and salt in a large pot. Add enough water to just cover the chicken. Bring the water to a boil. Once boiling, reduce the heat to a simmer and let it cook for 40 minutes.
Let the broth boil for 40 minutes, then taste the soup to check the seasoning. If it’s too bland, add more salt to enhance the flavor. Remove the cooked chicken from the soup and allow it to cool down.
Using a food processor, blend the steamed rice with chicken broth until they are well combined. You can use approximately 2 cups of steamed rice and 3 cups of water.
Transfer the blended rice porridge from the blender to a pot and set it on medium-low heat. Stir the porridge every 5 minutes to prevent the rice from sticking to the bottom of the pot. Gradually add chicken broth while stirring, ensuring that it blends well with the rice porridge.