Peel and slice the mangoes into small pieces.
Take about 2 liters of water, add red gram powder and boil.
Add the mango pieces and salt.
Boil until the mango pieces become tender and almost dissolve in water.
Add turmeric powder and rasam powder.
Boil for some more time.
Heat oil in a frying pan.
Splutter mustard seeds and then add the remaining ingredients and fry.
Add this to the rasam and allow to settle.
Preparation of rasam powder:-
Grind 100 gm of coriander seeds, 50 gm of cumin seeds(Jeerakam) and 30 gm of black pepper into a fine powder.