Toor dal - 1/2 cup
Curry leaves - few
Onion - 4 nos
Soak tamarind in hot water for few mins and squeeze the water.
Wash and remove skin of onion and edges of onions.Wash it again.
In a Kadai, add 2 tspns oil and fry the above masala ingredients without coconut till dal is brown. Transfer and Allow it to cool.In the same kadai, add 2 tspns of oil add onion and saute till soft. Add little salt.
Add coconut and few onions while grinding in mixie and grind it to a fine paste with little water.
Cook the toor dal, mash/whisk with water and keep ready.
Keep a vessel on stove and add tamarind water. Now add onion to this and allow it to boil and cook. Add salt and turmeric.
Add the grinded masala to it and boil.
Add few curry leaves.
Add dal mix well and allow it to boil. Add water if necessary.
Add jaggery for taste. Stir well and boil.(If you dont want you can skip jaggery part)
Heat oil and ghee in a kadai, add mustard, allow it to pop then add curry leaves.
Notes - Since this is Arachuvitta it will become thick when it cools, so adjust water accordingly.