Rinse the basmati rice under cold water, then combine with 0.5 cup water in a small pot; bring to a boil, cover, and simmer on low for 15 minutes.
While rice cooks, heat the ghee in a large skillet over medium heat and sauté the diced onion until translucent.
Stir in the minced garlic and grated ginger, cooking for 1 minute until fragrant.
Add the cubed chicken breast to the skillet, browning the edges for about 3-4 minutes.
Sprinkle in the garam masala, turmeric, cumin, sea salt, and black pepper, stirring to coat the chicken evenly.
Pour in the tomato puree and bring to a gentle simmer for 5-7 minutes until the chicken is cooked through.
Stir in the full-fat coconut milk to create a rich, creamy sauce and heat for an additional minute.
Fluff the rice with a fork and serve the butter chicken on top, garnished with fresh cilantro.