Soak the tamarind in water.
Wash the tur dal and cook it in the pressure cooker with a little turmeric powder.
Cut the drum stick into two inch pieces. Cook them in a pan with some water.
Cut the tomato into small pieces.
In a pan, add ghee and make the seasoning. Add mustard seeds, as it splutters, put asafoetida and turmeric powder, throw in the tomato with salt and some water. Let cook.
Extract the pulp from the tamarind.
Once the tomato are cooked, add tamarind pulp, rasam powder and curry leaves to it. Let boil.
Add cooked tur da and boiled drumstick to it. Put water, letcook on a low flame.
Once it boils, garnish with coriander leaves. Drumstick rasam is ready to serve.