Heat the ghee in a large skillet over medium heat until melted.
Add the diced yellow onion and sauté for about 5 minutes until translucent and soft.
Stir in the minced garlic and grated ginger, cooking for 1 minute until the mixture is fragrant.
Add the cubed chicken breast to the skillet and cook for 4 to 5 minutes until browned on all sides.
Stir in the tomato puree, garam masala, turmeric, sea salt, and black pepper until the chicken is well coated.
Reduce the heat to low, cover the skillet, and simmer for 10 minutes to allow the flavors to meld.
Remove the lid and stir in the full-fat coconut milk to create a rich, creamy sauce.
Steam the cauliflower rice until tender and serve the butter chicken over the top, garnished with fresh cilantro.