Take half cup coriander, half cup mint leaves, 10 green chilles, a pinch of salt and water. Grind it well in a mixer.
In a pan, heat oil and saute the onions till golden brown.
Now, marinate mutton with the ground masala, curd, garam masala, salt, chilly powder, 4 tsp lemon juice and add some ghee on the top. Refrigerate it for an hour.
Cook rice with garam masala, the rice should be semi cooked. Add coriander and mint leaves while cooking for fresh aroma.
Cook the marinated mutton in the pressure cooker for 5 whistles.
Now take a thick bottomed utensil, add one layer rice and one layer mutton. Add some ghee, fried onions and lemon juice to it.
Put it on the stove, on high flame for 5 minutes and on sim for 15 minutes.
The biryani is ready to serve.