In a small bowl, whisk together the Greek yogurt, half of the garam masala, turmeric, salt, and pepper.
Cut the chicken breast into 1-inch cubes and toss in the yogurt mixture to coat; let marinate for 15 minutes.
Cook the basmati rice according to package instructions until tender and fluffy.
Heat the ghee in a large skillet over medium-high heat and sear the chicken until golden brown on all sides, then remove from the pan.
In the same skillet, sauté the finely diced onion, minced garlic, and grated ginger until the onion is translucent.
Stir in the tomato puree and the remaining garam masala, simmering for 5 minutes until the sauce thickens.
Lower the heat and stir in the coconut milk, then return the chicken to the pan to simmer for another 5 minutes until cooked through.
Serve the creamy chicken tikka masala over the warm basmati rice and garnish with fresh cilantro.