Wash and pressure cook the dal with 1 ½ cup water and a pinch of turmeric powder for 3 whistles. Mash well and set aside.
Soak the tamarind in 1 cup warm water and extract the tamarind juice. If using tamarind paste, dissolve in 1 cup warm water.
Wash the ladies finger well, put on a towel or tissue paper and dry it completely. Trim the end and cut into 1 inch long pieces.
Heat a kadai and add 1 tsp coconut oil and ladies finger. Fry in medium-high flame until brown spots appear. Set aside.
In the same kadai, add 1 tsp oil and fry the shallots for 3-4 minutes. Add the fried ladies finger, tamarind extract, turmeric powder, sambar powder, red chilly powder and salt.
Bring to boil and boil until raw smell of tamarind goes. Then add the mashed dal, water if required and simmer for 4-5 minutes.
In a small pan, heat oil and add mustard seeds. When it crackles, add dry chillies, asafoetida and curry leaves. Pour over the sambar.