In a mixing bowl add in the cleaned fish pieces. To this add in Chilli powder, Turmeric powder, Pepper powder and salt. Mix everything together such that the masala is evenly coated over the fish. Finally add in the lemon juice. Allow it to rest for 1 hour.
Heat a pan or tawa with oil, once its hot add in the marinated fish pieces and the curry leaves.
Flip and cook on both the sides till the fish is fully cooked and golden brown. Once cooked remove from tawa and keep in paper towel for absorbing the excess oil.
Heat oil once its hot add in the Fennel Seeds, cinnamon Stick, bay Leaves, Black Stone Flower let it sizzle and then add in the sliced onions Saute till glossy and then add in the ginger garlic paste saute till the raw smell leaves.
Next add in the tomatoes. Cook till mushy. Mix well and then add in the chilli powder, Turmeric powder, Garam Masala, Coriander Powder and Salt. Mix well and then add in the coriander leaves and switch off the flame.
Cook the Rice and keep it ready. Mix the Saffron in milk and keep it ready.
Now take the vessel which the dum cooking is to be done. Layer it with the Masala Prepared. Add in chopped mint and coriander leaves. Place few fish sliced.
Now add in the half of the cooked rice sprinkle in the saffron milk and then add in the coriander and mint leaves and add few more fish slices.
Now place above the rest of the rice and then sprinkle in saffron milk and the mint coriander leaves Finally sprinkle in the fried onions.
In the lowest possible flame heat a dosa tawa and keep the dum vessel above that. Cook for 30 mins and then open the flame. Carefully fluff with a fork and then serve hot.