Heat oil in a pan and saute the prawns for a few seconds. Drain and keep aside.
In the same oil saute the onions till light brown.
Add the ginger-garlic paste and all the dry spices mixed with little water. Stir fry for a few seconds.
Add the tomato puree, oats and green chilies. Saute for a minute.
Add the boiled dal and water. Bring it to a boil and add the fried prawns. Simmer for 5-10 minutes or till it thickens to a desired consistency.
Add lime juice and garnish with coriander leaves. Enjoy as a light dinner or whenever you wish.