RASAM

Ingredients:

Yellow lentil (tur dal) - 1 cup;
Tamarind water - 1/2 cup;
Tomato puree - 1 cup;
Ginger-garlic paste - 1/2 tsp;
Mustard seeds - 1/2 tsp;
Cumin seeds - 1 tsp;
Turmeric powder - 1/2 tsp;
Black pepper powder - 1/4 tsp;
Red chilli powder - 1/2 tsp;
Curry leaves - chopped - 3 tbsp;
Vegetable oil - 2 tbsp;
Salt to taste.

Method:

Put the lentils in a pressure pan with turmeric and add 3 1/2 cups of water. You can pressure cook it or bring it to boil and let it cook over medium heat until tender (about half an hour). Keep aside.
Heat oil in a pan. Add  mustard seeds and cumin seeds and let it splutter.
Add red chilli powder, pepper powder, salt, tomato puree, ginger-garlic paste and cook for 4 minutes.
Add tamarind water and 2 tbsp curry leaves. Stir well and bring it to boil, reduce the heat and cook for 2 minutes. 
Blend the lentils in electric blender. Add it to the above puree. Also add 2-3 cups water and bring it to boil.
Serve hot. Garnish with curry leaves.