Fry 1/2 a cup of thinly sliced onions till golden brown. Drain and keep them aside. Slightly brown the raisins as well as the cashews. Keep them aside.
You have the option of cooking the rice separately.But I prefer to cook my rice in the chicken gravy. This I learnt from my sister. I belive this is the Tamilian way of preparing Biryani.
Heat up the ghee and add the remaining sliced onions when the oil is hot. Saute till it caramelises (the onion turns slightly brown) and then add the chillies, ginger, garlic , ground khuskhus and the ground masala powder and mix well. Now add tomatoes, mint leaves and coriander leaves and give it a toss. Add turmeric, curd, lemon juice, salt and chicken. I add 2-1/2 cups water to get enough gravy to cook my rice.
Once the chicken is cooked, I drain the chicken and keep it aside. Wash the cleaned rice and put in a pan/cooker. Add the chicken gravy which should be 3-3/4 cups- 4 cups. Mix and cook till the rice is well cooked and th gravy is absorbed. Mix with the cooked chicken. Garnish with the fried onions, cashews and raisins and a bit of finely chopped coriander leaves. Serve with Raita or Mirch ka salan.