Heat the oil in a heavy-bottomed pan over medium heat. Add the sliced onions and cook until golden brown.
Add the ginger and garlic pastes, sautéing for 2–3 minutes until aromatic.
Grind the soaked cashew nuts into a smooth paste and add to the pan, stirring well.
Add turmeric, coriander, cumin, and red chilli powders. Cook for 1–2 minutes.
Add chicken pieces and salt. Stir to coat evenly.
Gradually stir in whisked yogurt, mixing continuously.
Add cardamom, cloves, and cinnamon. Pour in 200 ml water. Cover and simmer on low heat for 15–20 minutes until chicken is tender.
Stir in garam masala, fresh coriander and double cream (if using) just before removing from heat.
