Dice the chicken breast into 1-inch cubes and place in a bowl with Greek yogurt, half the garam masala, turmeric, sea salt, and black pepper; toss to coat and marinate for 15 minutes.
Prepare the basmati rice according to package instructions and set aside.
Heat the ghee in a large skillet over medium heat, then add the diced yellow onion, minced garlic, and grated ginger, sautéing until the onion is soft and translucent.
Add the marinated chicken to the skillet and cook for 5-7 minutes, stirring occasionally until the chicken is browned on all sides.
Pour in the tomato puree and the remaining garam masala, stirring to combine and simmering for 8-10 minutes until the sauce thickens and the chicken is cooked through.
Lower the heat and stir in the full-fat coconut milk, allowing the sauce to become creamy and well-incorporated.
Serve the spiced chicken over the cooked basmati rice and garnish with freshly chopped cilantro.