Cut the chicken breast into bite-sized pieces and place them in a bowl.
Whisk together the Greek yogurt, half of the garam masala, and the turmeric, then coat the chicken and marinate for at least 15 minutes.
Heat the ghee in a large skillet over medium-high heat and sear the chicken until golden brown on all sides, then remove and set aside.
In the same skillet, add the finely diced onion and sauté until translucent and slightly caramelized.
Stir in the grated ginger and minced garlic, cooking for 1 minute until fragrant.
Pour in the tomato puree, the remaining garam masala, cumin, sea salt, and black pepper.
Bring the sauce to a gentle simmer and return the chicken to the pan, cooking for 5-7 minutes until the chicken is cooked through.
Stir in the coconut milk to create a rich, creamy texture and heat through for 1 minute.
Serve the chicken tikka masala over the warm cooked basmati rice and garnish with fresh cilantro.