Soak tamarind in ½ cup of water. Squeeze the pulp with your hands and strain the mixture. Set aside till use.
Start by cooking rice. Take washed rice in a pressure cooker, add 6 cups of water and pressure cook it for 5 whistle. Now simmer the flame and let it cook for 15 mins. Switch off the flame and let the pressure go all by itself. Set it aside.
Now cook the dal, take dal and cover it with water. Cook it for 2 whistle. Now simmer the flame and let it cook for 10 mins. Switch off the flame and let the pressure go all by itself. Set it aside.
Grind the ingredients given for the masala to a smooth paste by adding some water.
Now take all the vegetables in a large kadai. Cover with water and add salt to it. Bring it to a boil and simmer the pot. Let it cook for 20 mins till the veggies are done.
Now add in cooked dal and tamarind water and mix well. Cook it for 5 mins.
Add in the ground masala and mix well. Boil it for 5 to 10 mins.
Saute drumstick leaves in a teaspoon of oil till the leaves is wilted. Add this to the gravy and boil it.
Make seasoning by heating oil and crackling mustard and vadakam. Pour this into the gravy. Boil it for 5 more mins. Now the gravy is done.
Take rice in a large pot and pour enough gravy into it. Mix well.
Serve with thogayal and papad..