Rinse the basmati rice under cold water until the water runs clear, then combine with 0.5 cup water in a small pot and bring to a boil.
Reduce heat to low, cover, and simmer the rice for 15 minutes or until water is absorbed; fluff with a fork and set aside.
While rice cooks, cut the chicken breast into bite-sized cubes and season with sea salt and black pepper.
Heat avocado oil in a large skillet over medium heat and sauté the diced onion until translucent, about 5 minutes.
Add the minced garlic and grated ginger to the skillet, cooking for 1 minute until fragrant.
Add the chicken cubes to the pan and brown on all sides for about 5-6 minutes.
Stir in the garam masala, turmeric, and cumin, coating the chicken and onions evenly in the spices.
Pour in the tomato puree and stir to combine, allowing the sauce to simmer for 8-10 minutes until the chicken is cooked through.
Stir in the full-fat coconut milk to create a creamy sauce and simmer for an additional 2 minutes.
Serve the chicken tikka masala over the cooked basmati rice and garnish with freshly chopped cilantro.