Chop onion, ginger and tomatos finely. Slit green chillies lengthwise.
In a frying pan (kadai), put a tablespoon of oil and fry the rawa till it changes its colour. Remove it and keep it.
In the same frying pan, put the remaining oil and when it is hot, add the mustard. When it pops up, add cashew nuts and dhals and fry till it turns light brown. Add chopped onion, chillies, ginger and curry leaves. Fry till onions are transparent. Then add tomato pieces and fry till it mashes well. Add turmeric powder, red chilli powder and salt. Mix well. Add three cups of water and bring to boil. When it starts boiling, slowly add the fried rawa and stir continuously till it absorbs all the water and form like a ball.