The dal should have swelled, and you will be able to break the dal easily after soaking it for 1 to 1.5 hours.
Drain the water.
Add the lentils and fenugreek seeds to a high powered blender.
To this add garlic, ginger, green chilies, salt and turmeric.
Add 1/2 cup of water and blend until you get a smooth batter.
Be careful while adding water. You want to make sure your batter is thick. So that you can adjust the consistency later.
Once your batter is ready, pour it in a bowl. Now add 2 tbsp's of rice flour, finely chopped onions, cilantro and green chilies. Give it a mix.
Now add little water at a time to adjust the consistency. Your batter should be of pancake consistency. You don't want a runny batter. Rest the batter for 5 minutes.