Mix all the ingredients given under marination and coat the fish pieces nicely and leave it in the refrigerator for 40 minutes or best overnight.
Chop the shallots finely. Reserve 1/2 for seasoning.Peel the mango and cut into half moon size thick slices. Reserve a few pieces of peel to add to the curry (this brings out the mango aromas in the curry) Chop ginger finely and cut the green chili to big pieces.Grind the coconut, chili powder turmeric and salt to a fine paste and keep aside. Heat a heavy bottom pan and add coconut oil when that heats add the chopped ginger and saute. When the roasted aroma comes add the green chili, give it a minute then add the chopped shallots and curry leaves keep sauting until the shallots turn slightly brown.
Now add the coconut paste mix everything together and add 2 cups of water (Enough to cover the fish while cooking). Cover with the lid and allow this mixture to come to a boil.
Gently put the marinated fish pieces into the curry and scatter the mango pieces around it.Put the reserved mango peel too in to this. Cover and cook on medium to slightly low heat for 20 minutes. Check once or twice in between to make sure the fish is cooking evenly. As the curry cooks the coconut will thicken the curry.NOTE: Do not stir the fish pieces too hard as the pieces will fall apart and break. In a smaller pan heat some coconut oil and add fenugreek seeds. Allow this to become fragrant and slightly brown (not black and burnt) now add the shallots chopped and the curry leaves. When the shallot carmelizes season the whole thing with the oil on top of the Porgy fish curry. Keep aside for the flavors to mingle
Serve Porgy fish curry with steaming rice and other side dishes such as lentils and greens. I have served here with Feild beans stir fry and moringa leaves stir fry.