Drain channa dal add it to blender, peel green raw mango and cut into pieces, and coarse blend it with channa dal, add few spoons of water if needed, mixture should be thicker than chutney. add salt and sugar keep it aside.
Now in a pan add oil, mustard seed let it splitter, then jeera, curry leaves, chopped chilly, pinch of hing and spread it over the ambe dal.
If the mangoes are not sour then add few spoons of lime juice.