Make a coarse paste with coconut and the rest of the ingredients, except tamarind paste, water and curry leaves. Add very little water while grinding, if required.
Remove the paste into a pan and keep it on fire.
Add the water, tamarind paste and curry leaves. Mix well and bring to a boil.
Open the tuna can(s) and drain off the oil.
Add tuna to the gravy in the pan.
Cover and cook for about 6 minutes or till the tuna is cooked and coated with the gravy.
Remove from the flame.
Season it with mustard , dry chilli and curry leaves (if desired)..
:- Serve hot with warm rice and Coconut Pancakes (Appam), steamed rice or slices of bread.
:- This curry is supposed to be spicy and tangy. However, the amount of chillies and tamarind can be reduced or increased as desired.
:- Fresh tuna will taste very good in this recipe.