For preparing the kanji, combine the broken rice, water and salt in a pressure cooker and cook on high flame for 5-6 whistles. Switch off and allow to cool completely.
Grind the coconut along with the water till smooth. Pass through the seive and press well to extract as much as coconut milk. Discard the residue.
Open the lid and add the coconut milk. Simmer on low flame for a few minutes. Adjust salt. If the kanji is thick, add more water as per required consistency.
For the chammanthi, grind all ingredients in a grinder till coarse. Serve along with the kanji.