01 - Combine yogurt, lemon juice, oil, garlic, ginger, cumin, coriander, garam masala, paprika, salt, turmeric, and cayenne in a large bowl. Add chicken and toss to coat thoroughly. Cover and refrigerate for at least 30 minutes, preferably 2-4 hours for optimal flavor absorption.
02 - Rinse basmati rice under cold water until water runs clear. Combine rice, water, salt, and butter in a saucepan. Bring to a boil, reduce heat to low, cover, and simmer for 12-15 minutes until liquid is absorbed. Remove from heat, keep covered, and let stand for 5 minutes. Fluff with a fork before serving.
03 - Preheat grill or large skillet over medium-high heat. Thread marinated chicken onto skewers or place directly in skillet. Cook for 5-7 minutes, turning occasionally, until chicken is browned throughout and reaches an internal temperature of 165°F. Transfer to a plate and set aside.
04 - Heat oil in a large pan over medium heat. Add finely chopped onion and sauté for approximately 7 minutes until golden brown. Add minced garlic and grated ginger; continue cooking for 1 minute until fragrant, stirring constantly to prevent burning.
05 - Stir in cumin, coriander, paprika, chili powder, and garam masala. Cook for 1 minute, stirring continuously, until spices become highly aromatic. This technique, known as blooming, enhances the depth of flavor in the finished dish.
06 - Add crushed tomatoes and sugar to the spiced onion mixture. Reduce heat to maintain a gentle simmer and cook for 10 minutes, stirring occasionally to prevent sticking. The sauce should thicken slightly and develop a deep red-orange color.
07 - Pour in heavy cream and season with salt to taste. Simmer for an additional 5 minutes, allowing the sauce to emulsify and thicken. Add the cooked chicken pieces and simmer for 5 more minutes, enabling the flavors to meld together completely.
08 - Spoon generous portions of chicken tikka masala over steaming basmati rice. Garnish generously with freshly chopped cilantro for a vibrant finish and additional layer of flavor. Serve immediately while hot.