Rinse the basmati rice under cold water until the water runs clear, then combine with 0.4 cups of water in a small pot, bring to a boil, reduce to low, and simmer covered for 15 minutes.
While the rice cooks, cut the chicken breast into 1-inch bite-sized pieces and season them with sea salt and black pepper.
Heat the ghee in a large skillet over medium heat, then add the diced yellow onion and sauté for 4-5 minutes until translucent and soft.
Stir in the minced garlic and grated ginger, cooking for 1 minute until fragrant before adding the chicken pieces to the pan.
Brown the chicken for 3-4 minutes, then stir in the garam masala, turmeric, and cumin to toast the spices for 30 seconds.
Pour in the tomato puree and full-fat coconut milk, stirring to combine and scraping up any browned bits from the bottom of the skillet.
Reduce the heat to low and let the sauce simmer for 8-10 minutes until the chicken is cooked through and the sauce has thickened into a velvety consistency.
Fluff the rice with a fork and serve the spiced butter chicken over the top, garnished with freshly chopped cilantro.