Add salt as required to the Dudhi and cook using as little water as you can. (I use the pressure pan and switch off the gas when the steam is just generated). Don’t overcook it. Drain the water and cool the Dudhi .Don’t throw the water, use it for making Rasam or Dal or making Roti dough. Beat the curd with a spoon to make it homogenous and add to the cooked Dudhi. In a small pan heat oil, add the mustard seeds, once they crackle, add the Cumene seeds and last add the green chillies. Add this tadka to the Dudhi curd mixture. Add sugar and mix nicely. Adjust the salt if required.