Cook moong separately by adding salt and boiled water.
When it is cooked (don`t allow it to become too soft), drain it.
Heat oil in a kadai.
Add cumin seeds.
Add sliced onion and saute till it becomes light brown.
Add ginger-garlic paste and mix it well.
Add turmeric powder, chilli powder and coriander powder along with sliced tomato and smash it well.
Add 1 cup of water and little salt to the gravy and bring it to boil.
Add the cooked moong and garam masala to this gravy. Mix well.
Cover it with a lid and keep it on a low flame for 20 mins.
Remove from fire.
:- Serve hot with Chapathi, Appam, Roti or parotta.