Add all the ingredients under marination except the chicken in a large bowl and mix it well.
Make slashes on the chicken pieces and add it to the prepared yogurt marination and marinade for at least for an hour. the longer the better.
Heat 2 tbsp of in a large pan on medium heat and temper it with black cardamom, cinnamon, green cardamoms, cloves and black peppercorns. Saute for a minute.
When you get the aroma of the spices toss in the sliced onions.
Saute on medium heat for 12-15 minutes, stirring continuously until the onions turn soft and golden brown. (make sure the onions do not burn, keep the heat consistent over all). Now slowly take it out of the pan and let it cool.
Once the fried onion has cooled down a bit, add the fried onion along with the tomatoes, cashew nuts and almonds in a mixer grinder. Add 2 tbsp of water and ground it to a fine paste. Keep it aside for later use.
In the same pan add the rest of the oil and heat on medium high heat. Add the chopped ginger, garlic and green chillies and saute for 10-15 seconds.
Slowly add the chicken pieces along with the marinade in the hot oil and fry on medium high heat for 18-20 minutes stirring frequently so that it does not stick at the bottom.
Now add the ground paste to the chicken along with 1/2-3/4 cup of water and stir everything well. Cover and cook for 25-30 minutes on low flame, stirring frequently so that it does not stick to the bottom.
Check the seasoning. Add sugar/sweetener or salt if required. Cook the chicken curry until it is fully cooked through and you see oil floating on top. Turn of the heat.
For the dhungar, place a small piece of charcoal directly over a full flame. Turn the charcoal using tongs so that the flame reaches all the sides of the charcoal. Now place a metal bowl/aluminium foil in the prepared chicken curry and transfer the blazing charcoal with tongs into the center of the bowl. Now take a tsp of ghee and drop it over the charcoal, immediately put a tight lid on the pan. Let it smoke for 3-4 minutes. The smoke trapped inside will infuse a lovely smokey flavour to the dish.
Serve it hot with naans or parathas or rice.