Combine rice, black gram (urad dal), and fenugreek seeds in a bowl and wash until the water runs clear.

Add water to the rice mix to fill 3/4 of the bowl. Cover and let it soak overnight or at least 5 hours.

Drain the water from the rice mix after soaking. The rice grain should break easily in your hand.

Grind the soaked mixture with water (about 1 tbsp at intervals) into a smooth paste with no granules. The batter should be thicker than pancake batter.

If using a small grinder, grind in batches.

Transfer the batter to a large bowl, add salt, and mix well. Cover and let it rise undisturbed overnight or until it doubles in size.

If you don't want to make dosas immediately, refrigerate the batter after mixing well to prevent it from turning sour.

Dilute the batter to resemble pancake mix for a smooth flow.

Heat a non-stick skillet until a drop of water sizzles and evaporates quickly.

Pour a ladleful of batter onto the skillet and quickly spread it in a circular spiral motion.

Turn the heat to high and cook the dosa until it colors golden on the lower side. Apply a little oil, then flip and cook the other side.

Remove from skillet and serve immediately. Repeat with the remaining batter.

Wipe the skillet with a clean cloth before pouring batter for the next dosa.