Preheat the oven to 170 degrees C fan forced.
Add spices from the Rice Spice Mix sachet to a large saucepan.
Add 1 tbsp oil and 2 liters of boiling water to the saucepan.
Check the water for saltiness. It should be salty like the sea. If not, add more salt. This step is very important to ensure the rice is properly flavoured. The salt will be rinsed away later.
Drain the rice that's been soaking underwater. Carefully add it into the boiling water. Stir once, then allow the rice to cook on high heat for 4 mins.
After 4 mins, turn off the heat and strain the parboiled rice discarding the water. It is very important to not overcook the rice to avoid a gluggy Biryani.You now have fragrant, gently spiced riced all ready for layering. Assemble 3 layers of the Biryani. LAYER 1Evenly layer pieces of marinated chicken at the bottom of a deep and heavy pot. Unlike other forms of Biryani that first cook the chicken, our Hyderabadi version uses raw chicken for layering. Sprinkle half of the remaining mint and coriander over the chicken.
LAYER 2Gently spread the parboiled rice over the chicken in an even layer. Do not press down on the rice. (Optional) Sprinkle the saffron milk over the rice if using.
LAYER 3This final layer is made by spreading fried onions, mint, coriander and ghee over the rice. Even sprinkle fried onions from the sachet over the rice. Next spread the remaining mint and coriander
Finally drizzle 2 tbsp ghee or melted butter as the final step of this assembly.
Cover the pot with aluminium foil and put the lid on. The Biryani is ready to go into the oven.Cook the Biryani in the oven for 1 hour at 170 degrees C with the lid tightly secure. Carefully take the pot out of the oven and allow to stand for 15 mins with the lid on. Remove the lid and foil just before serving.