Whisk together the coconut aminos, honey, minced ginger, minced garlic, and arrowroot powder in a small bowl until smooth to create the teriyaki sauce.
Dice the chicken breast into bite-sized pieces and season evenly with sea salt and black pepper.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet and cook for 5-6 minutes, stirring occasionally, until golden brown and cooked through, then remove the chicken and set aside.
In the same skillet, add the broccoli florets with a small splash of water, covering with a lid for 2 minutes to steam until they are vibrant green and tender-crisp.
Return the chicken to the pan and pour the prepared teriyaki sauce over the mixture.
Toss everything constantly for 1 minute until the sauce thickens into a glossy glaze that coats the chicken and broccoli.
Serve the stir-fry immediately over the warm cooked brown rice and garnish with sesame seeds.