Boil sliced onion and cashews in water for 8 minutes; blend to a smooth paste.
Heat ghee in a pan, add ginger paste, garlic paste, and nut-onion paste; cook for 4 minutes.
Add cubed chicken breast and sear on medium flame for 5 minutes.
Whisk yogurt with heavy cream, cardamom powder, and salt; pour into the pan with water.
Cover and simmer on low heat for 12 minutes until chicken is tender.