In a small bowl, whisk together the tamari, honey, toasted sesame oil, grated fresh ginger, and minced garlic to create the teriyaki glaze.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Season the diced chicken breast with sea salt and black pepper, then add it to the skillet and cook until golden brown and cooked through.
Remove the chicken from the skillet and set aside on a plate.
Add the broccoli florets and sliced red bell pepper to the same skillet with a tablespoon of water, covering with a lid for 2 minutes to steam-sauté.
Remove the lid and continue to cook the vegetables for another minute until they are tender-crisp and bright.
Return the cooked chicken to the skillet and pour the teriyaki glaze over the mixture.
Toss everything together for 1 minute until the sauce thickens slightly and coats the chicken and vegetables evenly.
Serve the hot stir-fry immediately over the cooked brown rice.