Prepare the chicken marinade by combining 1 cup pineapple, yogurt, 2 tablespoons cilantro, 2 tablespoons lime juice, 1/4 teaspoon salt, red pepper flakes, and chili powder in a food processor and blending until smooth.

In a large bowl, marinate the chicken in the mixture, cover, and refrigerate for 1-3 hours.

Pulse cauliflower florets in a food processor until they resemble rice.

Heat canola oil in a large skillet over medium-high heat and sauté chopped red onion until lightly browned (3-5 minutes).

Add the cauliflower rice to the skillet and cook, stirring until lightly browned (5-7 minutes).

Stir in the remaining 1 cup pineapple, lime juice, and salt, then cover and cook over medium heat until the cauliflower is tender (3-5 minutes).

Stir in the remaining cilantro and keep warm.

Preheat grill or broiler.

Drain the marinated chicken, discarding the marinade.

Grill or broil the chicken until a thermometer reads 165°F (4-6 minutes per side).

Let the chicken rest for 5 minutes before slicing.

Divide the cauliflower rice mixture among four bowls.

Top with sliced chicken, remaining pineapple, and optional toppings like toasted coconut and lime wedges.