In a large mixing bowl, whisk together pineapple juice, lime juice, grated ginger, and tamari. Add the chicken, ensuring it's well-coated in the marinade. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes.

While the chicken is marinating, rinse the brown rice under cold water until it runs clear. In a medium saucepan, combine the rinsed rice with coconut milk, water, and a teaspoon of turmeric. Bring to a boil, reduce to simmer and cover for 40-45 minutes.

Preheat your grill or oven to 375°F (190°C). Remove the chicken from the marinade and place it on the grill or a baking sheet. Cook for 20-25 minutes, until the chicken reaches an internal temperature of 165°F (75°C) and juices run clear.

Once everything is ready, fluff the coconut rice and divide it among serving plates. Top with the chicken and sprinkle with toasted coconut flakes.