Rinse the basmati rice under cold water until clear, then combine with 0.5 cup water in a small saucepan; bring to a boil, cover, and simmer on low for 15 minutes.
While the rice cooks, dice the chicken breast into one-inch cubes and season evenly with sea salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat and sear the chicken until golden brown on all sides, then remove the chicken and set aside.
In the same skillet, add the diced onion, minced garlic, and grated ginger, sautéing for 3-4 minutes until the onion is translucent and fragrant.
Stir in the garam masala and ground turmeric, toasting the spices for 30 seconds before adding the tomato puree and coconut milk.
Whisk the sauce until smooth and bring to a gentle simmer, then return the seared chicken to the skillet.
Cook for an additional 5 minutes until the sauce has thickened and the chicken is fully cooked through.
Fluff the cooked basmati rice with a fork and serve the chicken tikka masala over the rice, garnishing with freshly chopped cilantro.