In a small bowl, whisk together the Greek yogurt, lemon juice, turmeric, and half of the garam masala.
Cut the chicken breast into bite-sized pieces and toss in the yogurt mixture to coat; let marinate for 15 minutes.
Heat the ghee in a large skillet over medium heat, then add the diced onion, grated ginger, and minced garlic, sautéing until the onion is translucent.
Add the marinated chicken to the skillet and sear for 5 minutes until the edges are browned.
Pour in the tomato puree, sea salt, black pepper, and the remaining garam masala, then reduce heat and simmer for 10 minutes.
Stir in the coconut milk to finish the sauce, allowing it to warm through and thicken slightly.
Serve the chicken and sauce over the warm basmati rice and garnish with freshly chopped cilantro.