Soak tamarind in hot water and extract tamarind juice. Make it 2 cups. I usually pressure cook it when I cook rice, keeping separately in a small bowl. It is easy for extraction.
Heat a kadai with oil, temper with ¼ teaspoon methi seeds, ½ teaspoon mustard, 1 teaspoon toor dal, 1 torn red chilli, asafoetida and curry leaves.
Add ¾ cup chopped orange peel, 3 slit green chilli. Stir fry for a minute.
Add ¼ teaspoon turmeric, little salt and cook further more for a minute.
Add to tamarind extract. Add 2 teaspoon sambar powder, required salt and boil for 4-5 minutes.
Once it reduces in volume, add idli chilli powder, mix well.
Add jaggery, boil until the kuzhambu thickens. Switch off flame.