- Heat oil, add mustard seeds, when it splutters, add fenugreek seeds and tur dal, when dal starts changing color, add hing, red chillies and saute for a few seconds. Then add manathakkali vathal and fry for a few seconds. Then add salt, sambar powder and curry leaves. Saute for a few seconds and then add tamarind extract . Mix well and cook on medium flame until it thickens and leaves oil. It will take around 10-20 minutes to thicken. As it cools it will thicken further, so do not allow it to become too thick. Serve.