For idli -- First in a pressure cooker add washed and soaked dal along with salt, turmeric powder and green chilli.add required amount of water and cook for 2 whistle.

Heat oil in a pan, add cumin seeds, mustard seeds, fenugreek seeds,curry leaves, let them crack, add hing stir and add onion,stir for a min, add tomatoes and all chopped veggies.stir well.Add salt and cook for few minutes until vegetables gets soft.

Add sambhar masala stir well, add tamarind water (soak 1/4 cup of tamarind in warm water,mash well and strain). Add cooked dal.Stir well.

Add 2-3 cup of water and let it come to a boil, after that reduce the heat and cook for another few minutes.

Add fresh chopped coriander leaves. Switch off the heat.

For idli-- in a bowl add semolina,curd and salt mix well and keep aside to rest for 10 -15 mins.add baking soda and mix well. heat a idli steamer grease each mould with little oil.Now pour idli batter in each mould,cover with lid and steam for 10 mins.

Idli sambhar is ready to serve.