If a smoother sauce is preferred, blend all marinade components (excluding chicken) into a purée using a food processor. This step is optional.
In a mixing bowl, combine the chicken pieces with all the marinade ingredients. Cover and place in the refrigerator to marinate for a minimum of 3 hours, ideally overnight or up to 24 hours.
Heat ghee (or the alternative fat) in a large frying pan over high heat. Remove the chicken from the marinade, ensuring not to scrape off the excess coating. Place the chicken directly into the pan; do not pour the leftover marinade in. Sauté for approximately 3 minutes until the exterior of the chicken turns white. Note that it won’t brown due to the yogurt-based marinade.
Reduce the heat to low and pour in the tomato passata, cream, sugar, and salt. Incorporate any remaining marinade from the bowl. Simmer gently for 20 minutes, stirring occasionally. Adjust salt to taste.
Garnish with chopped cilantro if desired and serve alongside basmati rice. For an added touch, accompany with no-yeast flatbread or microwave-puffed papadums.