In a small bowl, whisk together the tamari, honey, rice vinegar, arrowroot starch, minced garlic, grated ginger, and red pepper flakes to create the sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the cubed chicken breast to the skillet and sear until golden brown and cooked through, approximately 5 to 7 minutes.
Add the broccoli florets to the pan with a splash of water, then cover with a lid for 2 minutes to steam until they are vibrant green and crisp-tender.
Pour the prepared sauce over the chicken and broccoli, stirring constantly for 1 minute until the sauce thickens into a glossy glaze.
Remove the skillet from the heat and stir in the toasted sesame oil.
Serve the glazed chicken and broccoli over the warm brown rice and garnish with sesame seeds and sliced green onions.