In a bowl, combine the diced chicken breast with Greek yogurt, half of the garam masala, turmeric, sea salt, and black pepper. Let marinate for at least 15 minutes.
Heat the ghee in a large skillet over medium-high heat. Add the marinated chicken and sear until golden brown on all sides, then remove chicken from the pan and set aside.
In the same skillet, add the finely diced yellow onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and grated ginger, cooking for another minute until fragrant.
Pour in the tomato puree and the remaining garam masala. Bring to a gentle simmer for 10 minutes to allow the flavors to meld.
Stir in the full-fat coconut milk to create a rich, orange sauce, then return the chicken to the pan.
Simmer for an additional 5 minutes until the chicken is cooked through and the sauce has thickened.
Serve the chicken tikka masala over the warm, cooked basmati rice and garnish with fresh chopped cilantro.