Heat oil in a pan over medium heat.
Add the red chillies. Roast until they become crisp and slightly darker in colour. Do not let it burn. Transfer to a plate.
Next, add the chana dal. Roast it on medium flame till it becomes aromatic and golden brown. Transfer to the plate.
Add the Urad dal. Roast till it becomes aromatic and golden brown. Transfer to the plate.
Finally, add the sesame seeds. Saute for a few mins or till it splutters. Remove and keep it aside.
Allow all the roasted ingredients to cool down to room temperature.
Combine the roasted ingredients, asafoetida, and salt in a grinder or food processor.
When the powder is almost done, taste and adjust the salt if needed. At this point, you can add some jaggery if desired. Grind them together. Adjust the coarseness of Idli podi based on your preference.
Idli Milagai Podi is done. Store it in a clean, dry airtight container.
Serve with idli , dosa. Drizzle some sesame oil on top of it while serving.