In a medium bowl, combine the diced chicken breast with the Greek yogurt and half of the garam masala, turmeric, and cumin. Let the mixture marinate for at least 15 minutes to tenderize the meat.
Rinse the basmati rice under cold water until the water runs clear. Combine the rice with 0.5 cup of water in a small saucepan, bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes.
While the rice cooks, heat the ghee in a large skillet over medium heat. Add the diced yellow onion and sauté until it becomes translucent and slightly golden.
Stir in the minced garlic and grated fresh ginger, cooking for about 1 minute until the aromatics are fragrant.
Add the remaining garam masala, turmeric, cumin, sea salt, and black pepper to the skillet, stirring constantly for 30 seconds to toast the spices.
Pour in the tomato puree and bring the sauce to a gentle simmer.
Add the marinated chicken and any remaining yogurt from the bowl into the skillet. Cover and simmer for 8 to 10 minutes, or until the chicken is fully cooked through and the sauce has thickened.
Fluff the cooked basmati rice with a fork and plate it alongside the chicken tikka masala. Garnish with freshly chopped cilantro before serving.