Rinse the basmati rice under cold water until clear, then cook according to package directions until fluffy.
While rice cooks, dice the chicken breast into bite-sized pieces and season with sea salt and black pepper.
Heat coconut oil in a large skillet over medium-high heat and sear the chicken until golden and cooked through, about 5-6 minutes.
Remove chicken from the skillet and set aside on a plate.
In the same skillet, add the diced onion, minced garlic, and grated ginger, sautéing until the onion is translucent and fragrant.
Stir in the garam masala and turmeric, toasting the spices for 30 seconds to release their oils.
Pour in the tomato puree and simmer on low for 5 minutes to allow the flavors to meld.
Whisk in the full-fat coconut milk until the sauce is smooth and creamy.
Return the cooked chicken to the skillet, stirring to coat thoroughly in the masala sauce.
Serve the chicken masala over the warm basmati rice and garnish with freshly chopped cilantro.