Ingredients:
Tamarind - a marble sized ball
Salt to taste
Yam - 1 1/2 cups, chopped and peeled
Raw Green Plantains - 2 medium sized, peeled and cut into 1/4 inch cubes

Spice Powder:
Oil - 2 tsp
Dry Red Chillies - 2 to 3
Bengal Gram Dal - 1 1/2 tblsp
Uncooked Rice - 2 tsp
Asafoetida Powder - 1/2 tsp

Tempering:
Oil - 1 tsp
Mustard Seeds - 1 tsp
Black Gram Dal - 1/2 tsp
Cumin Seeds - 1/2 tsp
Dry Red Chilli - 1, halved
Curry Leaves - few

Method:
1. Soak the tamarind in 1 1/2 cups of water for 10 minutes. Extract the juice. Add the turmeric powder and salt to the tamarind juice. Set aside.
2. In a frying pan, heat 2 tsp of oil. Fry all the ingredients for the spice powder till the dal turns golden and spices give out their aroma. Remove from heat and grind to a fine powder in a blender.
3. In the same frying pan heat 1 tsp of oil and add all the ingredients for tempering. When the mustard seeds splutter, add the yam. Saute for 1 minute and add the tamarind juice.
4. Cover pan and simmer for about 10-12 minutes. Add the chopped plantains and cook for another 8-10 minutes till all the water is absored. If a little water remains, open the pan and cook till dry.
5. Stir in the spice powder.
6. Serve hot.