In a medium bowl, combine the cubed chicken breast with Greek yogurt and half of the garam masala, turmeric, and cumin.
Let the chicken marinate for at least 20 minutes to tenderize the meat and infuse the aromatic spices.
Heat the ghee in a large skillet over medium heat, then add the diced onion, cooking until translucent and soft.
Stir in the minced garlic and grated ginger, sautéing for 1 minute until the mixture becomes fragrant.
Pour in the tomato puree and the remaining spices, then bring the sauce to a gentle simmer.
Add the marinated chicken to the skillet and cook for 8-10 minutes until the chicken is opaque and the sauce has thickened.
Season the dish with sea salt and black pepper to taste.
Serve the chicken tikka masala over the warm, fluffy basmati rice and garnish with freshly chopped cilantro.