Prepare Chicken: Toss chicken thighs with 1 tsp turmeric and a pinch of salt. In a large frying pan, heat sunflower oil and brown the chicken on both sides. Remove chicken and set aside.

Sauté Onions: In the same pan, sauté the chopped onion for about 5 minutes until it softens.

Prepare Paste: Remove the flesh from one mango and combine in a food processor with the korma paste, ginger, and quartered onion to create a smooth paste. Cook this paste in the pan until it softens.

Add Spices: Stir in the remaining turmeric, ground cumin, and black onion seeds, and cook for a few minutes to release the flavors.

Simmer: Return the chicken to the pan, add coconut milk and chicken stock. Bring to a simmer, cover, and cook for 20 minutes.

Uncover & Cook: After 20 minutes, uncover the pan and continue cooking for an additional 25-30 minutes until the chicken is tender, adding water if needed to maintain a saucy consistency.

Add Mango: Slice the remaining mango and add it to the pan. Shred the chicken using two forks, allowing the mango to heat through. Season with salt as needed.

Serve: Garnish with fresh coriander and serve the curry alongside basmati rice, naan bread, mango chutney, and lime pickle if desired.