For the batter:

1. Soak the whole green moong dal, raw rice and fenugreek seeds for 5-6 hours. Over night is fine too. After soaking, drain the water and grind the mixture to a fine paste along with the cumin seeds, ginger, green chillies, and salt. Add upto a cup of water while grinding.

For making Pesarattu:

1. Heat the dosa griddle until medium hot.
2. Add ⅓ cup batter and swirl to completely cover the dosa griddle. Sprinkle ¼ teaspoon of oil or ghee to the pesarattu.
3. Cover the skillet with a pan and cook for 30 seconds. Cook until underside of the pesarattu dosa is golden brown. Loosen the edges of the pesarattu dosa with a steel spatula. Flip the pesarattu dosa. Cook for 30 seconds more. Remove pesarattu dosa from the griddle and repeat with remaining batter.