what i do is boil fish bones with fenugreek seeds (1tsp) and lemongrass (1stalk).
then add unripe papaya (slices, half a small papaya).
simmer for 1-2 hours (use slow cooker also can).
when wanna drink that time then add fresh sliced fish, boil for around 3-5min then drink.
so that fish wont be overcooked