Fry chopped onion till light brown
Fry all the above masala ingredients till changes colour
Wet grind fried masala ingredients and 1/4th of fried onion.
Keep paste aside.
Mix tamarind paste in water (180 ml) add salt, fried onion, pinch of turmeric powder and asafoetida in a saucepan bring it to boil.
Add cooked toor dal boil for 5 mins(add water if required)
Add sambhar masala paste boil further for few mins.
Heat oil put mustard seed allow to sputter , add to onion sambhar.
Garnish with coriander leaves .
Serve with hot rice.