Soak moongin two cups of water for minimum four hours.
Remove the water& keep it aside.
Grind moongwith ginger, garlic, green chillies and salt to a smooth batter .Add some water(kept aside) if needed to make the consistency of batter like that of dosa batter.
Add red chilli powder,chopped onions and mix well. Heat a ceramictawaand spread a ladle full of batter to a thin disc. Cook on medium heat till the underside is done.
Carefully flip over and cook till the other side is done too.