Mix everything well and layer the chicken evenly at the bottom.
Spread drained rice in a layer over the chicken.
Pour water to a separate pot.
Add salt, and mix. Taste the water, it must be slightly salty. Bring it to a rolling boil.
Pour 2 cups of this water across the sides of the pot with the chicken and rice. Gently pour the rest on the top of the rice.
Level the rice if needed. Sprinkle the rest of the mint leaves. Optionally, add fried onions and saffron soaked in milk if using.
Cover and cook on a medium burner until the rice in the chicken biryani is cooked completely but not mushy or undercooked. If the rice is still undercooked, or hard and there is no water at the bottom, pour ¼ to ½ cup more boiling water depending on the brand of the rice used to cook further. When done, is has to be fully cooked, yet remain grainy but not mushy.
Serve from the top to the bottom layer. Each serving gets biryani rice from top and chicken from the bottom layer.
Enjoy the biryani with raita and sliced veggies.