Step 1: Prepare the Marinade - In a large bowl, combine yogurt, lemon juice, turmeric, garam masala, chili powder, cumin, ginger, and garlic. Mix well, then add the chicken and coat thoroughly. Cover and refrigerate for at least 3 hours, ideally overnight.
Step 2: Sear the Chicken - Heat ghee or butter in a wide pan over high heat. Remove chicken from marinade and place into the hot pan with the coating intact. Do not add leftover marinade yet. Cook for 3 minutes until chicken turns white all over, stirring occasionally.
Step 3: Build the Sauce - Lower heat and add tomato passata, cream, sugar, salt, and any remaining marinade. Stir to combine. Let simmer for 20 minutes, until the sauce thickens and coats the back of a spoon. Adjust salt to taste.
Step 4: Final Touches and Serve - Sprinkle with chopped coriander if using. Serve hot with basmati rice, naan, or quick papadums for a satisfying meal.
