Soak idli rice, urad dal, methi seeds, and sabudana for 6-8 hours (except salt).

Grind the soaked ingredients into a slightly coarse batter.

Grind cumin seeds and pepper into a coarse consistency.

Prepare a tempering by heating ghee and gingelly oil in a tadka pan.

Add hing and mustard seeds to the heated oil; let them splutter.

Add urad dal, bengal gram, ginger, cashew, cumin & pepper powder, and curry leaves to the tempering and cook.

Mix the prepared tempering into the idli batter.

Allow the batter to ferment for 6-8 hours or overnight.

Clean the thonnai (dried leaves) with a wet cloth.

Pour the fermented idli batter into 3/4 of each thonnai cone.

Arrange the filled thonnai cones tightly in a pressure cooker or idli pan.

Steam the idlis for 20 minutes.

Remove from heat and let cool for 5 minutes before serving.