Cut the chicken into pieces and rub 1/2 teaspoon of turmeric and salt.
Heat the ghee in a pan and brown the meat. Take out of the pan and set aside.
Peel the mangoes. Dice the flesh of a mango and set aside. Mix the meat of the other mango with the Korma paste, the ginger and the quartered onion in the food processor to form a paste.
First, fry the chopped onion in the pan until soft, then add the paste and bring to the boil. Add the rest of the turmeric, cumin and nigella and after 3 minutes add the chicken, coconut milk and chicken stock. Cover the pan and let it simmer. After 20 minutes, cook for another 20 minutes without a lid.
Shred the chicken into pieces with 2 forks. Add the mango cubes and let them get hot. Sprinkle with coriander to serve.