Prepare the brown rice according to package instructions and set aside.
In a small bowl, whisk together the coconut aminos, rice vinegar, honey, sesame oil, arrowroot powder, and red pepper flakes to create the sauce.
Cut the chicken breast into bite-sized cubes and mince the garlic and fresh ginger.
Heat avocado oil in a large skillet or wok over medium-high heat.
Add the chicken cubes to the skillet and cook until browned on all sides and cooked through, about 5-7 minutes.
Remove the chicken from the skillet and set aside; add the broccoli florets and sliced red bell pepper to the same pan with a splash of water.
Sauté the vegetables for 3-4 minutes until tender-crisp, then stir in the garlic and ginger for 30 seconds until fragrant.
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 evenly.
Serve the stir-fry over the cooked brown rice and garnish with sliced green onions and sesame seeds.