In a small bowl, whisk together the tamari, honey, toasted sesame oil, grated fresh ginger, and minced garlic to create the teriyaki sauce.
Cut the chicken breast into bite-sized cubes and season evenly with sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet and sear for 4-5 minutes, stirring occasionally, until golden brown and cooked through.
Remove the chicken from the pan and set aside, then add the broccoli florets, sliced bell peppers, and carrots to the same skillet.
Stir-fry the vegetables for 3-4 minutes until they are tender-crisp and bright in color.
Return the chicken to the skillet and pour the prepared teriyaki sauce over the mixture.
Toss everything together for 1-2 minutes until the sauce has thickened slightly and coated all ingredients.
Serve the stir-fry immediately over the warm cooked brown rice and garnish with sesame seeds.