In a wide mud pot/pan, crush together small onions, green chilli, ginger, curry leaves, salt and vinegar. Crush well for 3-5 minutes.
Move it to one side and add turmeric powder, coriander powder and chilli powder to the same pan.
Drizzle coconut oil and mix the masala well and mix it again with the crushed onions.
Once the base is ready, add the raw mangoes and mix gently.
let the mixture sit for 10 minutes.
After 10 minutes, cook the mixture with thin coconut milk.
Let it cook until mangoes are soft. Put off the flame and add the thick coconut milk.
mix gently and prepare the tempering.
Heat coconut oil in a separate pan and add broken red chillies, sliced onions, curry leaves and a pinch of salt.
fry till slightly brown. Add the tempering to the curry and mix well.
Close and let it sit for a few minutes for flavours to get blended. Serve it hot with rice and thoran.