• In a large bowl combine ragi flour, semolina, salt, curd and water. Mix it well and rest the batter for 20 - 30 minutes.
• While the batter is resting do the tempering. Heat oil and urad dal and cumin seeds and fry till dal turns light brown. Add cashew, ginger, finely chopped green chili and curry leaves. Fry for a minute and add a pinch of asafoetida and turn off the stove.
• After 20 minutes add this tempering to the ragi-rava mixture. Mix it well. Check for the batter consistency and add some water if needed. The batter should be similar to idli batter. Slightly thick, but pourable. 
• Add eno and little water on top of the eno to activate it. Mix it.
• Grease your idli plates with oil/ghee/cooking spray. After the eno is added, you will almost immediately see bubbles in the batter. Immediately pour a ladle full of batter in to idli molds and steam them for 10 - 11 minutes.

Steaming in the instant pot -

• Add 1.5 cups of water and boil it in the saute mode. Once the water comes to a boil, hit cancel. Place the idli mold and close the lid. Turn the pressure valve to vent position. Press the steam mode and keep an external timer for 10 minutes. Once the timer is done, turn off the instant pot and remove the idli after 5 minutes.

If using Idli Steamer -

• Steam the idli on high for 10 minutes. Remove once the pressure releases naturally.

If using traditional pressure cooker -

• do not place the whistle and steam them for 10 minutes.
• To check if the idli is done, if you stick a knife into the idli and it should come out clean. After you remove the idli mold from the steamer, let rest for 2-3 minutes before removing the idli.