Peel and cut 1/2 kg of onions in half, then slice them lengthwise into medium thickness.

Separate the layers of the sliced onions to ensure even frying.

Heat oil to 135°C (not too hot) in a pan. Add the sliced onions, ensuring the oil level is just up to the surface of the onions.

Fry the onions on high flame initially, stirring occasionally, until they turn light golden brown. Control the temperature to avoid burning by lowering the flame if needed. This process takes about 15-20 minutes.

Once the onions are light golden brown, remove them from the oil to prevent overcooking due to carry-forward cooking. Gently press with a spoon to drain excess oil.

Spread the fried onions on tissue paper using a fork to give space and dab with another tissue if necessary to remove excess oil. Let them rest for 5-6 minutes.

Heat a pan on high heat, then reduce to minimum. Add coriander seeds, cumin seeds, caraway seeds, green cardamom, black cardamom, cinnamon, black peppercorns, spicy red chillies, bay leaves, cloves, and mace.

Roast the spices on low flame until a slight fragrance is noticeable and they warm up. Avoid burning them.

Add dried fenugreek leaves (Kasuri Methi) and lightly mix. Transfer the spices to a bowl to cool down.

Once cooled, transfer the spices to a mixer-grinder. Add grated nutmeg, turmeric powder, and a pinch of salt. Grind to a coarse powder.

Take 1/2 kg chicken (leg and thigh pieces) in a large bowl. Add salt to taste, juice of 1 lemon, ginger-garlic paste, green chilli paste, Kashmiri red chilli powder, turmeric powder, coriander powder, and 1.5 tbsp of the prepared Biryani masala.

Add 3-4 tbsp of the leftover oil from frying onions. Mix well to coat the chicken properly with the spices.

For immediate cooking, whisk 200 ml curd nicely and add it to the chicken along with 80% of the prepared Birista, optional potato, chopped mint, and coriander leaves. Mix well.

Smoke the marinated chicken by placing a burning coal in a small bowl, adding some ghee to it, and covering with a lid for 2-3 minutes to impart a smoky flavor.

Heat 2 tbsp ghee in a thick-bottomed pot. Add the marinated chicken and cook on high flame for 5-6 minutes to sear it well.

Lower the flame, cover, and cook the chicken for 10-12 minutes until it is 85-90% cooked. Check and adjust seasoning if necessary.

Bring water to a rolling boil in a stock pot. Add bay leaves, cinnamon, caraway seeds, green cardamom, cloves, star anise, black peppercorns, slit green chillies, juice of half a lemon, lemon skin, and salt (water should be as salty as seawater).

Take 1/2 kg basmati rice, washed 3-4 times, and soaked for 1-1.5 hours. Drain the soaking water and add the rice to the boiling water.

Cook the rice for 4-5 minutes until 90% cooked, stirring lightly to avoid breaking the grains. The rice should have a slight bite.

Remove the rice from hot water using a spider, spread it on a large platter, and fluff it lightly with a fork to release excess steam. Let it rest for 5-10 minutes. Remove lemon rind and whole spices if desired.

In the pot with cooked chicken, spread the chicken pieces evenly at the bottom. Add chopped coriander, mint leaves, a pinch of Biryani masala, and some reserved Birista.

Gently layer the cooked rice over the chicken, ensuring not to break the grains. Spread it evenly.

Add 3-4 tbsp warm ghee over the rice, spread evenly. Prepare an emulsion of water, milk, and saffron, and spread it over the rice for color and aroma.

Sprinkle additional chopped coriander, mint leaves, and the remaining Birista on top of the rice.

Cover the pot with a wet muslin cloth or wet dough on the rim, place a lid on top, and apply pressure. Place the pot on a griddle pan over a stove.

Cook on high flame for 5 minutes, then lower to minimum flame and cook for 10-15 minutes to give 'Dum' to the Biryani.

Turn off the stove and let the Biryani rest for at least 10 minutes before opening the lid. Serve after resting.