In a medium bowl, combine the diced chicken breast with the Greek yogurt and half of the garam masala, turmeric, and cumin, then let it marinate for at least 15 minutes.
Heat the ghee in a large skillet over medium-high heat and sear the marinated chicken until golden brown on all sides, then remove the chicken from the pan and set it aside.
In the same skillet, add the diced yellow onion, minced garlic, and grated ginger, sautéing until the onion becomes translucent and fragrant.
Pour in the tomato puree and the remaining spices, stirring well and allowing the mixture to simmer for about 5 minutes until the sauce thickens slightly.
Lower the heat and stir in the coconut milk to create a creamy consistency, then return the seared chicken and any accumulated juices back into the skillet.
Continue to simmer the mixture for another 5 to 7 minutes until the chicken is fully cooked through and the sauce is bubbling.
Garnish the skillet with freshly chopped cilantro and serve immediately while hot.