Make idly as usual.cook dal with turmeric and yellow pumkin in pressure cooker.
Cut onion and tomato into smallpieces.
Take a pan add oil put mustard and urad dal, fry onion and tomato one by one add tamarind pulp, salt and tamarind water,add curry leaves and hingboil it for 10 mins,add cooked dal, sambar powder,salt, water,and boil it for 10 mins.
Garnish with corriander. Take a plate keep idly and pour the sambar and add ghee.