Rinse the basmati rice under cold water until the water runs clear. Combine with 0.4 cups of water in a small pot, bring to a boil, then reduce to low, cover, and simmer for 15 minutes.
Cut the chicken breast into 1-inch bite-sized cubes and season with sea salt and black pepper.
Heat the olive oil in a large non-stick skillet over medium-high heat. Add the chicken and cook until browned on all sides, about 5-6 minutes. Remove chicken from the pan and set aside.
In the same skillet, add the diced onion and sauté for 3 minutes until translucent. Add the minced garlic and grated ginger, cooking for another 60 seconds until fragrant.
Stir in the garam masala, turmeric, and cumin, allowing the spices to toast for 30 seconds.
Pour in the tomato puree and bring to a gentle simmer. Return the chicken to the pan, cover, and cook for 5-7 minutes until the chicken is cooked through.
Remove the skillet from the heat and stir in the Greek yogurt until the sauce is creamy and well-combined.
Fluff the rice with a fork and serve the chicken tikka masala over the top, garnished with freshly chopped cilantro.