Cook the brown rice according to package instructions and set aside.
In a small bowl, whisk together the coconut aminos, rice vinegar, honey, and arrowroot powder to create the sweet and sour sauce.
Heat the sesame oil in a large skillet or wok over medium-high heat.
Season the diced chicken breast with sea salt and black pepper, then sear in the skillet until golden and cooked through.
Remove the chicken from the pan and add the diced bell peppers, yellow onions, minced garlic, and grated ginger.
Sauté the vegetables for 3-4 minutes until tender-crisp, then stir in the cauliflower rice and fresh pineapple chunks.
Return the chicken to the skillet and pour the prepared sauce over the mixture, stirring constantly until the glaze thickens and coats everything evenly.
Serve the sweet and sour chicken over a base of the cooked brown rice.