Take the mutton pieces in a bowl, add the whipped yogurt, 1 cup of beresta, ginger-garlic paste, red chili powder, nutmeg powder, crushed mace, cloves, green cardamoms, cinnamon, oil and salt. Give it a hearty mix. This is a very important step for a good kachhi biryani.
Keep the marinated mutton aside, at least 3-4 hours, even better if overnight, in the refrigerator.
Smear the potato halves with a pinch of turmeric powder and a little salt. Heat ½ tbsp of oil and lightly fry the potatoes. Keep aside.
Soak the saffron strands in warm milk. Keep aside.
Soak the basmati rice for 20 odd minutes. Drain the water.
Cook the rice in boiling water, just a few drops of oil and a pinch of salt added to the water, till about 20% done. Drain the water. Spread the semi-cooked rice on a flat dish, keep aside.
Take a heavy bottomed pan, grease with 1 tbsp ghee. Transfer the marinated mutton along with the marinade to the pan, spread evenly.
Place the potatoes and a little crushed beresta over the marinate mutton.
Cover evenly with the rice. Sprinkle the remaining beresta over the rice.
Gently pour the saffron infused milk, keora water and the remaining ghee evenly over the rice.
Cover the lid, seal firmly with flour dough. Place the pan on another flat frying pan, cook over a low flame for 2 hrs.
A standing time of 10 odd minutes and the biriyani is ready to serve.