In a small bowl, whisk together the fresh orange juice, tamari, honey, and arrowroot powder until smooth.
Season the cubed chicken breast 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 sauté for 5-6 minutes until golden brown and cooked through, then remove and set aside.
In the same skillet, add the broccoli florets, sliced red bell pepper, minced ginger, and minced garlic.
Stir-fry the vegetables for 3-4 minutes until they are tender-crisp and vibrant in color.
Return the cooked chicken to the skillet and pour the orange sauce mixture over the top.
Simmer for 1-2 minutes, stirring constantly, until the sauce thickens into a glossy glaze that coats the chicken and vegetables.
Serve the stir-fry immediately over the warm, cooked brown rice.