Make four slashes parallel to the bone on the chicken thighs. Mix the thighs, onion, juice and paprika together until the meat is well coated. Set aside for a few minutes.
Mix together the yogurt, ginger, garlic and spices, then pour over the chicken and mix well. Refrigerate over night.
Fire up the oven to 220 degrees celcius. Cover the roasting pan with aluminum foil and spray with Pam. Place the thighs on top of the foil, skin side down, then roast for 20 minutes, turn and roast for another 15 minutes. Brush the skin with the ghee and broil for about 5 minutes.