soak tamarind in 2.5 cups water and take out the extract from it.
mix together onion, green chiilli, curry leaves, mangoes and squeeze it with your hands.
further add chopped coriander leaves, turmeric powder, chilli powder, coriander powder, sambar powder, salt and tamarind water.
mix well add a pinch of hing/asafoetida and cook it for 10-15 minutes.
mash the mangoes slightly and then add jaggery to taste
mix well and cook until the curry thickens.