In a pressure cooker add soaked tuwar dal, salt, turmeric powder, green chillies, chopped pumpkin and as required water. Cover with lid and cook for 3-4 whistles. Let the pressure release by itself and then whisk the dal well. Keep aside.

Next in a wok/pan heat oil, once heat add mustard seeds and let them splutter, add curry leaves, asafoetida and red dried chillies.

Further add onion and green chillies saute for a min. Add chopped tomato and Salt cook for a min or until tomatoes gets soft. Then add Sambhar masala, mix well.

Now add whisked dal along with as required water and let it come to a boil then switch the flame on medium heat and cook for 10 mins. switch off the flame, add fresh coriander and mix.

For making Vada -- first in a bowl soak urad dal in enough water for 3 hours.

Drain off the water and grind to fine fluffy paste by adding water as required.

Transfer the urad dal paste into large mixing bowl. beat and mix the batter in circular motion till they turn light. this helps to incorporate air into batter and make medu vada soft and fluffy

Further add ginger- chilli paste, fresh coriander chopped, dry coconut, hing, rice flour and salt.

Mix the batter well with the help of spoon. Heat the oil in large kadai. wet your hands with enough water and take a small ball sized dough and make it round.
Now slowly shape the edges and make a hole at the centre with the help of your finger.

Drop the vada in oil and deep fry the medu vada on medium flame. Fry on both sides till they turn golden brown and crisp. Next drop the fried vada into warm water and add with little salt.

Soak for 10 minutes or till vada absorbs water.Squeeze off the water and place the vada into a plate.Pour the prepared sambar over vada.
finally, sprinkle few chopped onions and serve.