Take a cup of minapappu or urad dal, wash it twice, and soak them for 5-6 hrs.
Add the minapappu to a blender.
Grind them to a smooth and tight batter adding very little by little water.
In a mixing bowl, beat the batter for 4-5 minutes. By doing this we will get very soft and fluffy garelu. If you are grinding the batter in a wet grinder, skip this. Add salt to the batter and mix well. just add the salt.
Meanwhile, heat the oil in a kadai.
When the oil is hot enough, wet your hands and take a big lime size ball of batter. Flatten the batter using your thumb and make a hole at the center. You can also make them on a thick plastic cover or on a banana leaf.
Slowly slide the batter into the oil and fry it on a medium flame.
Similarly, make the other vada's.
When the vada starts turning golden, flip them and fry till golden on both sides.
Serve hot garelu with idli, chutney and sambar.