In a small bowl, whisk together the coconut aminos, rice vinegar, honey, minced ginger, minced garlic, and arrowroot powder until smooth.
Cut the chicken breast into bite-sized pieces and season with sea salt and black pepper.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat.
Add the chicken to the skillet and sear until golden brown and cooked through, approximately 5-6 minutes, then remove from the pan and set aside.
Add the sliced red bell pepper and red onion to the same skillet, sautéing for 3-4 minutes until the vegetables are tender-crisp.
Stir in the pineapple chunks and cook for another minute to warm through.
Return the chicken to the skillet and pour the sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce thickens and coats the chicken and vegetables beautifully.
Serve the stir-fry immediately over the warm cooked brown rice.