Add the boneless chicken, salt, black pepper, cumin powder, coriander powder, garam masala and gram flour to a blender or food processor.
Add the sliced onions, fried onion, green chillies, garlic, ginger, mint leaves, coriander leaves and egg.
Blend everything well. While blending, add 1 tablespoon of oil.
Shape the mixture into small kofta balls and set them aside.
To prepare the curry mixture, add the fried onions, yogurt, tomatoes, red chilli powder, turmeric powder, coriander powder, chilli flakes and ½ cup water to a blender. Blend until smooth.
Heat ⅓ cup oil in a pan. Add the black cardamom and cumin seeds, and sauté for a few seconds.
Add the blended curry mixture and cook for 3 minutes.
Add another ½ cup of water and cook on low heat for 3 more minutes.
In a separate pan, heat a little oil and lightly fry the koftas for about 2 minutes, just until they develop some colour.
Carefully add the fried koftas to the curry. Cover and cook on low heat until the koftas are fully cooked and the curry thickens.
Garnish with fresh coriander and serve hot with naan, roti or rice.