Preparing the Chicken:

1. 1. Marinate the Chicken: In a large mixing bowl, combine the yogurt, lemon juice, oil, and all the spices for the marinade. Add the chicken pieces and mix until well coated. Cover and refrigerate for at least 1 hour, preferably overnight, for maximum flavor infusion.

1. 1. Grill the Chicken: Preheat your grill or oven to a high temperature. Skewer the marinated chicken pieces and grill until cooked through, about 5-7 minutes per side. Remove from heat and set aside.

Making the Sauce:

3. 3. Cook the Onions: In a large pan, heat the vegetable oil over medium heat. Add the chopped onions and sauté until they turn golden brown.

3. 3. Add Garlic and Ginger: Stir in the minced garlic and grated ginger, cooking for an additional minute until fragrant.

3. 3. Incorporate the Spices: Add the ground cumin, coriander, turmeric, chili powder, and garam masala. Stir well to coat the onions in the spices, cooking for another minute.

3. 3. Add Tomato Puree: Pour in the tomato puree, stirring to combine with the spices and onions. Let it simmer for 10-15 minutes, allowing the flavors to meld.

3. 3. Finish with Cream: Reduce the heat to low and slowly stir in the heavy cream. Cook for another 5 minutes, adjusting salt to taste.

3. 3. Combine Chicken and Sauce: Add the grilled chicken pieces to the sauce, ensuring they are well coated. Simmer for an additional 5-10 minutes to allow the chicken to absorb the flavors of the sauce.

3. 3. Garnish and Serve: Sprinkle with fresh cilantro before serving.