Soak the moong dal for 4-5 hrs with enough water to keep it immersed. Rinse and drain.
Add this to a blender jar. Add the rest of the ingredients and blend to a smooth batter. Add maybe ¼ -½ cup of water, little by little as needed, while grinding.
Rest the batter for 10-15 mins or so
Heat a skillet. Take about ½ cup of the batter and spread it out on to the skillet like a crepe. Drizzle a little oil, if needed. Wait for it to cook - you will see it change color a little, maybe even crisp up a little and will look cooked through on top.
Using a wide spatula, flip this over to cook the other side too. It should all take about 3-4 mins over medium heat.