Wash and Soak rice for 30 mins. Now boil lots of water with all the ingredients given for cooking rice. Add the soaked rice in the water and cook it for 8 to 10 mins till the grains are 90 percentage cooked. Drain it in a colander and set aside.
Mix saffron with warm milk and set aside to steep.
Marinate the fish in the ingredients given for 30 mins. Heat oil in a heavy bottom pan(this is the pan where you are going to make briyani). Add the fish pieces in this oil and cook them for 5 mins on each side. Remove them to a plate.
In the remaining oil, add in pandan leaves and fry them for few mins. Add in sliced onions, green chilli and saute for 5 mins or so.
Once the onion is cooked, add in ginger garlic paste and saute them for a min.
Now add in all the spice powders and mix them for 30 sec.
Add in tomatoes and a splash of water. Cook this for 5 mins till the tomatoes is mashed completely.
Add in salt, mint leaves, coriander leaves and curd. Mix well.Cook this for 5 mins till the masala is completely cooked.
Now spoon the cooked rice on top and add some more coriander and mint leaves. Drizzle over some saffron milk and place the fish pieces on top of the rice.
Cover this whole thing and place over a heavy bottom iron tawa and put the tawa on low heat. Let this whole thing be on dum for 15 to 20 mins. Open the lid and mix everything up.