Rinse the basmati rice under cold water until the water runs clear, then combine with 0.5 cup water in a small pot, bring to a boil, cover, and simmer on low for 15 minutes.
While the rice cooks, cut the chicken breast into bite-sized 1-inch cubes and season with the sea salt and black pepper.
Heat the ghee in a large skillet over medium heat; add the diced onion and sauté for 4-5 minutes until translucent and soft.
Stir in the minced garlic, grated ginger, garam masala, and turmeric, cooking for 1 minute until the spices become incredibly aromatic.
Add the chicken cubes to the skillet, browning them on all sides for about 3-4 minutes to lock in the juices.
Pour in the tomato puree and full-fat coconut milk, stirring well to combine and scraping up any browned bits from the bottom of the pan.
Reduce the heat to low and simmer the sauce for 8-10 minutes until the chicken is cooked through and the sauce has thickened.
Fluff the rice with a fork and serve the butter chicken over the top, garnished with the fresh cilantro.