I have eaten many versions of this iconic dish from Kerala (?) though some historians say the dish may have been brought to the Western Malabar Coast by Portuguese . The recipe that I have liked the most is from Sumeet Nair's cookbook The Bangala Table , for it's simplicity and this is how my mother's hand written recipe book too more or less has it.
500 Grams fish- I lightly sauted mine and set aside. This step isn't in the recipe.
2 Tablespoons Vegetable Oil.
3 Green Chilies Julienned .
12 Medium Shallots.
10 Curry Leaves.
3 Large Garlic Cloves Sliced- I used 7.
1" Ginger Peeled and Julienned/ Sliced long and thin.
1/2 Teaspoon Turmeric Powder.
1 Cup Thin Coconut Milk***
1.5 Cups Thick Coconut Milk***
1 Teaspoon Lemon Juice.
***I simplified the method and used 2 cups of coconut milk extracted from one coconut.
Heat oil , when hot but not smoking add curry leaves , shallots , ginger and garlic.Stir well , after 30 seconds add haldi . Saute on low till onions begin to soften , but don't allow them to color. I added some coconut milk and cooked covered for 2 minutes till onions softened.
Add the coconut milk , simmer to develop flavors for about 5-7 minutes , it will thicken a bit too , now slide in the fish and simmer for another minute or two till fish is done.Add lemon juice , adjust flavors - How delicious this was !