Blend yogurt, onion, tomato puree, garam masala, red chili powder, lemon juice, ginger and garlic paste. Marinate the chicken in the blended mixture for at least 2 hours.
Heat 1/2 cup oil in a cooking pan, add the marinated chicken to the pan and cook on medium heat for 20 minutes.
Burn a lump of coal in the meantime and place it in a heat-safe dish. Place that dish on top of the curry and pour 1 tsp oil on the coal and cover for 4 minutes.
Garnish with coriander and green chilies, serve with naan and enjoy!